The 100 Girlfriends Who Really, Really, Really, Really, Really Love You: Mimimi considers Nano her rival due to Nano having beaten her in their junior high beauty contest. It turns out that her hatred actually stems from Nano snubbing her after the contest, and she ends the rivalry when Nano apologises to her.
Arifureta: From Commonplace to World's Strongest: Kaori initially believes that she's Yue's rival for Hajime's affection. Some time later, she realises that she's actually Shea's rival for the position of second lover.
Jean Kirstein is the cynical Jerkass to Eren's idealistic hero. The two immediately come into conflict due to their differing ideas, and nearly end up putting things behind them. That he ends up falling for Eren's beautiful, violently-protective foster sister results in him becoming a Green-Eyed Monster and adds further fuel to their rivalry. However, Jean ends up accurately predicting that Eren's lack of forethought would come back to haunt him and proves to be the better soldier of the two. It turns the whole trope on its head, however, in that Jean doesn't end up coming over to Eren's side because of anything the latter did, but rather through Jean's own personaltragedies and development into a promising young leader.
The series later introduces a darker Foil to the above, with the childhood rivalry between Jerk Jock Porco Galliard and idealistic Heroic Wannabe Reiner Braun. As children, Galliard's Brutal Honesty brought him into repeated conflict with Reiner and led to blows more than once. As Warrior Candidates, they competed to inherit the Armored Titan and become the 4th member of the team being sent to Paradis Island. Their relationship as adults isn't much better, with Galliard blaming Reiner for the death of his brother and convinced things would have worked out better if he'd won over Reiner. For his own part, Reiner accepts this criticism and neglects to tell him that Marcel rigged the selection process in Reiner's favor....to protect Galliard.
Yuno is this to Asta, with the two being foster brothers and best friends who push each other to become stronger in their shared goal of becoming the Wizard King. Despite being The Stoic, he takes their rivalry even more seriously than Asta does.
Leopold Vermillion declares himself to be a rival to Asta after seeing him fight at the Distinguished Service Ceremony. Asta takes it in stride and the two have a Friendly Rivalry as a result.
BanG Dream! has Ran Mitake of Afterglow and Yukina Minato of Roselia, who view each other as Rivals, which pushes each of them to make their bands better. Interestingly, they have more in common than they might care to admit, each being the lead vocalist and lyricist of their own bands, and each one wants to impress their fathers with their music, though for different reasons.
Bleach: Ichigo's had several over the years, but his most notable rival is arguably Grimmjow (who serves as his Evil Counterpart), whose hatred of him borders on obsession. What started as an attempt to outdo Ulquiorra eventually lead to arguably the most intense grudge between two people in the entire series. The animosity between Grimmjow and Ichigo finally reached a boiling point in the Hueco Mundo arc, where the two finally had an uninterrupted fight in which Ichigo won. He returns during The Thousand Year Blood War to aid Ichigo and the others in their attempt to defeat the ultimate enemyYhwach, if only to guarantee a rematch with Ichigo.
Cage of Eden Yarai considers Akira to be his rival, though the two are on much better terms than many other anime rivalries. Segawa even points out that Akira is Yarai's first real friend, and that's why he can't kill him, even with Nishikiori's threat to let Kurusu die hanging over his head.
In Cap Revolution Bottleman, Hokari Ryo is one to Cota Coga, being the first opponent who Coga challenges to a Bottleman battle. They have arguments and struggle to team up in training until the end of the season, when they team up against the final opponent, Yujiki and George Muto.
Cardcaptor Sakura has Syaoran Li, who starts off as Sakura's rival for collecting all the Clow Cards because, as Clow Reed's descendant, he sees himself as their rightful owner. He's initially abrasive to the point of being a Jerkass and puts Sakura down as a "weakling", but Character Development (and being passed over by Sakura for worthiness of the cards) makes him mellow out significantly to stop being a rival to her and instead become something else.
Child of Kamiari Month: Yasha is a young oni descended from a clan of demons who were originally tasked with collecting the offerings for the divine feast, and seeks to regain that honor by surpassing Kanna. However, they grow to be friends over the course of their journey together. It's revealed that Yasha also had this dynamic with Yayoi, Kanna's mother.
In City Hunter, Umibozu is Ryo's rival. During the story they're Vitriolic Best Buds or, when finding themselves on opposing sides, Friendly Enemies, but Ryo's American acquaintances revealed it's a fairly recent development and that they used to be Arch-Enemies.
Suzaku Kururugi. It's little more complicated than the norm though. Suzaku plays friendly enemies with Lelouch Lamperouge, due to their friendship but drastically opposed viewpoints. Though Lelouch is initially not aware, and feels quite betrayed when he finds out, he sort of understands Suzaku's views and situation, going so far as to save him twice, despite it. Up until the second season, where things get... generally more violent, and their respective actions, much less forgivable.
On the other hand, Kallen and Suzaku more easily fit the mould of the rival, with both being exceptional pilots, and the same ultimate goal.
Death Note: Light Yagami and L are classic examples, foils with similar traits, differing ideals and near-opposite appearances to offset their near-identical approaches to problems. They suffer from a serious case of Rivals Team Up under odd circumstances as well, though it both was and wasn't true teamwork.
Half the cast of the Dragon Ball franchise has had this relationship with Goku at one point or another, Vegeta being the most prominent example in Dragon Ball Z, with Yamcha being the first in the original Dragon Ball.
Vegeta is notable for setting the template for cocky and smug rival characters in fiction, but Vegeta himself is something of an Unbuilt Trope. For all his bluster, Vegeta is almost always on the backfoot in his rivalry with Goku. His drive to push himself to surpass Goku is double edged sword, as he often subjects himself to Training from Hell and doesn't let his body properly rest, thus stunting his gains compared to Goku's more Boring, but Practical training methods. His inability to catch up to Goku only fuels his own feelings of inferiority, and at times is presented as being almost childlike levels of patheticness. It reaches its boiling point in what fans have dubbed "Vegeta's mid-life crisis", where he pulls a Face–Heel Turn in the name of gaining more power, committing several heinous acts in the process. Which only hammers in how idiotic it was in hindsight when he finds out Goku was holding back in their battle and had achieved another tier of Super Saiyan beyond 2. It ultimately isn't until Vegeta himself finally starts taking strides to improve himself and learning from those more powerful than him does he start to get more on equal grounds with Goku, and finally manages to beat him fair and square for once,with no strings attached.
Hakuoh and Kokujo from Duel Masters, the former doing a total 180 in every aspect after Shobu beats him, while the latter never really stops being the rival, softening only the slightest bit.
Julia of Fairy Idol Kanon is this to Kanon and her friends, while her mother Hijiri was once this to Marika's mother Manami.
Fairy Tail: Gray Fullbuster is Natsu Dragneel's main rival. He also can be considered this to Lyon.
Kenshiro had Shin and later Raoh as a primary rival in Fist of the North Star. His friendly rival/brother-in-kung-fu Rei had Juda as his.
Falling in Love With the Villainess: Captain Frederic serves as this to Rion, being one of the few people in the world who can curbstomp Rion, and the guy Rion hopes to grow strong enough to beat one day.
Rin considers Haruka his rival in Free!. It's a little one-sided, as Haru doesn't like to compete and doesn't seem especially interested in beating Rin. However, when they were children, Haru was miffed that Rin seemed to "understand the water" more than he did. It is commented on later that Haru is actually more fired up when it comes to Rin, and by the time Rin and Haru reconcile, they've gone on to heatedly competing over silly competitions like catching crabs and who gets the better fortune.
Eas in Fresh Pretty Cure!, mostly toward the protagonist Love than the other Cures. Complete with pretending to be friends to try and sabotage their team from within and a Deconstruction of Becoming the Mask which amps up Eas' side of the rivalry then cranks up Love's end after the inevitable betrayal leading into a very personal duel where Love even told the other Cures not to get involved. This being Pretty Cure, friendship trumps everything and Eas pulls a Heel–Face Turn after she and Love work things out.
Char Aznable from Mobile Suit Gundam was so popular and influential that any rival in the Gundam franchise is an Expy of him.
Athrun Zala is Kira's rival in the original Mobile Suit Gundam SEED and probably his main rival overall. This is a unique example for the Gundam franchise in that they know a lot about one another. They were childhood friends and often find it difficult to fight one another. The show milks this dynamic for all it's worth, having Athrun attempt to capture Kira alive and having oodles of fun when messing around with the dynamic the two boys' love interests have.
From Mobile Suit Gundam SEED Destiny Kira Yamato and Shinn Asuka are rivals to each other. Although this case in interesting in that neither of them know anything about each other nor each others names. They meet once but say very little and don't know who the other is. This somewhat changes after Kira kills Stellar with the Freedom and Shinn's considered the Freedom (and it's pilot, Kira) to be his Arch-Enemy. In fact, once Shinn upgrades to Destiny, Kira doesn't even know he's the same pilot he's fought before, while Shinn only know the Strike Freedom as the upgraded version of Freedom and assuming they have the same pilot. So they are effectively faceless enemies to each other for their entire rivalry.
In Mobile Suit Gundam 00 Graham Aker is the rival to Setsuna F. Seiei. Interesting in that Graham is at first a typical mecha pilot, but it's in Season 2, after we've met him, that he becomes the traditional Char Clone. When the movie comes around Graham has come to understand Setsuna's perspective and prays for his recovery so they can both fight the oncoming alien threat.
Jerid Messa is Kamille Bidans's rival in Mobile Suit Zeta Gundam. Their rivalry is definitely one fueled by revenge, and is actually more of a mutual hatred than just a rivalry, considering they both have taken the lives of many important people in the other's life. However, due to a bad case of Can't Catch Up, Jerid rapidly ceases to be a credible threat against Kamille, no matter how hard he trains or how new and cutting-edge his mobile suit is.
Anavel Gato and Kou Uraki become rivals in Mobile Suit Gundam 0083: Stardust Memory. At first Gato considers Kou as nothing more than a rookie that's in over his head, but soon enough he recognizes him as a worthy foe after their duel and the destruction of the GP-02A and the GP-01Fb
Treize and Wufei are portrayed as rivals as well. They meet when Treize challenges Wufei to a sword duel, and after losing, Treize respects Wufei's honor, while Wufei has a begrudging respect for Treize's strength and a burning desire to defeat him. Their rivalry comes to an end with Treize dying with a smile on his face at Wufei's hands.
Played for Drama in Mobile Suit Gundam AGE: Asemu and Zeheart become this due to their shared highschool time together, yet got into different side of war: Asemu sided with Earth Forces, and Zeheart sided with Vagan, similar with Kira and Athrun's Gundam SEED example above.
In Gundam Build Fighters, Sei and Reiji have a few rivals, from Mao, Fellini, Nils, and Aila, but the only true rival for them is Yuuki Tatsuya, a.k.a. the third Meijin Kawaguchi.
In Gundam Build Fighters TRY, each of TRY Fighters' members have the rival in Celestial Sphere team: Sekai with Wilfrid Kijima, due to both of them are passionate Gunpla Fighters that respect each other as the Worthy Opponent; Yuuma with Saga Adou, due to the latter has humiliated the former in the Gunpla Battle so bad that make him trauma and not participate into Gunpla battling until two years later; and Hoshino with Shia Kijima, beside the Gunpla battle's reason, somewhat they are rivaling each other because both of them has attracted to Sekai.
Domon Kashu from Mobile Fighter G Gundam is interesting in that almost his whole Five-Man Band can be considered his rivals, even after they are corrupted with and later cured of DG Cells and join his team. The local Char, Schwartz Bruder does not count as a rival, as he serves more as a mentor.
A one-sided example with Kitty. She views Sandybell as a rival for Mark's affections, but Sandybell doesn't hold any contempt for her. Nevertheless, Kitty will always try to be one step ahead of Sandybell, from using her wealth to get a higher position at her job, to gaining access to special events that could lead to breaking news stories, to pursuing the drug gang the newspaper company ran stories on...only to get kidnapped by them.
Alec also hates Sandybell for her happy-go-lucky view on life and decides to resort to dirty tricks to getting one aver her at their newspaper job.
Alucard and Alexander Anderson are this in Hellsing. Due to Anderson's humanity, regenerator abilities, and ridiculous levels of determination, Alucard views him as a Worthy Opponent and relishes every fight they're able to engage in, sometimes even overlooking his primary mission in order to fight him. And although Alucard visibly breaks when Anderson forsakes his humanity in a bid to defeat him, he still respects the priest in the end and understands why Anderson made the choice that he did.
As a whole, the Axis Powers (Italy, Germany and Japan) serve as this to the Allied Forces (America, England, France, Russia and China) during the World War II strips.
Sweden and Denmark in the past, with a history of wars rivaling England and France, over their competition for control of the Baltic and Scandinavian regions (with Denmark most often on the losing end). In the present, though, things have calmed down, and Denmark proclaims that he and Sweden are now the best of friends.
The Netherlands has warred in the past with Spain, who gave him the noticeable scar on his forehead during one of their conflicts. Netherlands also warred with Portugal in an attempt to dominate maritime trade and make Macau his own.
Russia and America during the Cold War. Though they're no longer enemies in the present, they're still rather tense and passive-aggressive toward one another.
A lighter example is Ladonia, who sees Sealand as this, due to the fact that Ladonia wishes to take Sealand's place as leader of the micronations. Sealand doesn't reciprocate, and instead is fond of Ladonia and calls him "interesting."
Czech Republic sees Hungary as this where spas are concerned, as she's adamant that her very famous spas are seen as the best in the world. Hungary doesn't reciprocate.
In High School D×D, the most obvious rivalry out there is between Issei Hyoudou and Vali Lucifer. They stand opposite each other in so many ways:
To start, their Sacred Gears directly oppose each other (Boosted Gear periodically doubles in power while Divine Dividing has the power to halve an opponent's power in the same interval).
Furthermore, inside their respective Sacred Gears are two legendary dragons who are themselves long rivals (Ddraig and Albion).
Even their perversions oppose. Issei is infamous as being a T man. It turns out Vali is secretly an A man.
Akira to Hikaru in Hikaru no Go: The series premise makes turning evil and/or the need for a rescue, embarassing or otherwise, highly unlikely. Mass quantities of Foe Romance Subtext are used, seemingly to make up for it.
Rei Asagiri to Eriko Tamura. She is Tamura Productions' established star and her rock music concerts draw in as much as fans as Eriko's pop concerts do. Yuusuke views her as a tool to overthrow Eriko's popularity. She already hated Eriko before, and the narration even describes Eriko feeling as if "a knife sliced between her eyes" when she met Rei for the first time.
Attempted with Hiroshi Osawa. Ryoko Asagiri tries to use him as a means to dethrone Eriko from fame. However, Hiroshi has no interest in the talent business and cares only for music.
IGPX: Immortal Grand Prix: When Takeshi Jin was hired by Team Satomi, incumbent pilot Riven felt put out by the decision, and the two were bitterly at odds until Riven finally decided to quit and join rival Team Sledgemama. As it turned out, Takeshi connected with Riven much better as a rival, and they've since become much friendlier.
Claire was supposed to be this, competing with Rei for the affections of one of the three princes and intended "capture targets." Instead, she's the target of Rei's affections.
Manaria is a straighter example as she is most definitely willing to steal Claire's heart if Rei isn't willing to step up.
Takahashi Keisuke (specifically, because he best fits the "intolerable ass" requirement), and at least half the cast of Initial D.
Shirogane and Kaguya from Kaguya-sama: Love Is War are depicted as academic rivals, who are always competing for the top spot during the end of semester exams (in addition to being hopelessly in love with each other). This was actually invoked on Shirogane's part. Kaguya completely ignored his Dogged Nice Guy attempts to court her when they were freshmen, so he set out to become the type of person that she would view as an equal.
Kingdom has two other young commanders — Mouten and Ouhon — competing with Shin for achievements and promotions in the Qin military. However, the former is such a nice, friendly guy who helps Shin out that he doesn't really seem like one. The latter is a more typical rival who comes from nobility, complete with complex relationship with his family, who looks down on the protagonist for his humble origins.
In Kitsune no Yomeiri Kanon the Tanuki considers herself to be Kyouka's rival and tries to defeat her in everything possible whenever they meet but always fails.
In the manga, Mary was this to Sarah because they both had crushes on Arthur, and were toe-to-toe when it came to their skills. In the anime, this is retained to Mary and Sarah being rivals at painting, where Sarah's skill level far exceed's Mary's. In season two, Mary comes to view all of Saint Patrick's as this for the Lady's Crest, particularly Vivian and Lynn, and decides she'll knock them out of the game Nomatterwhat.
Vivian Spencer is this to Lynn Russell, as they're both skilled equestrians that have eyes for Edward Brighton. She is always haughty to Lynn and belittles her every chance she gets. Mary knows that Vivian is the likeliest to get the Lady's Crest, so she sets her up against Lynn. When Vivian falls off her horse and it's revealed the reins were cut, Lynn is blamed and disqualified (when it was actually Mary who did it). Edward and Arthur put two and two together and tell Vivian that Lynn is innocent. Vivian feels stupid for letting Mary use her, and tells the Principal that Lynn deserves to compete in the tournament. He allows it.
Magical Girl Lyrical Nanoha A's had one Wolkenritter to match up against each of the main combatants on the cast; Signum vs. Fate, Vita vs. Nanoha, and Zafira vs. Arf. Signum and Zafira were more like Worthy Opponents to their respective counterparts, but Vita plays the trope straight.
Magical Girl Lyrical Nanoha StrikerS has Agito vs. Reinforce Zwei until the former is adopted by the Yagami family and they have developed a friendly Sibling Rivalry. Also downplayed with the unspoken rivalry between Nanoha and Teana — despite them starting off teacher and student, respectively, they quietly compete over who is the best sharpshooter of their generation (Nanoha is only three years older), if the mock battles in ViVid are any indication. Also, over being the bigger influence on Subaru.
Magical Girl Lyrical Nanoha ViVid had Einhart to Vivio, and she was the Unknown Rival to Ixpellia in the beginning of the season, but Einhart has become a Friendly Rival and the best friend of Vivio and she has given up on Ixpellia, who lies in a coma anyway. Many of the Inter-Middle Championship participants have a strong rivalry to each other. Harry vs. Victoria, Els vs. Harry, and many participants are rivaling Sieglinde, especially Micaiah has the strongest resolve to defeat her. Vivio gained another rival of the Friendly Rival type, Miura Rinaldi, who has a similar role as Vita and Signum to Nanoha and Fate, respectively.
Magical Record Lyrical Nanoha Force has the Hückebein Family, who are opposing Special Duty Section 6. Among the Hückebein members who are rivals to several SDS6 members, there are Curren vs. Hayate, Veyron vs. Thoma, Cypha vs. Signum, and Arnage vs. Isis. It also looks like there will other up-coming rivalries between DeVille and Fate, and Rosalia and Lily.
Tension flared between her and Yan-Min, right from the start, due to the latter calling Maken-ki weak. So Azuki dared her to prove it. Yuuka kept them from fighting, but they eventually traded blows during the Venus arc. While Azuki emerged the victor, she later admitted it was only because Yan-Min had held back. So she asked her to return to Tenbi so they could have a proper rematch.
Mazinger Z: Boss was The Rival from The Hero Kouji Kabuto. He was jealousy of Kouji because he was a better bike rider AND Sayaka had a crush on Kouji. The first thing he did when they met was picking a fight with him. However, as the plot and Character Development marched on, he slowly grew to respect him, and they eventually became friends (Boss still tried to compete with Kouji for Sayaka's heart, though). Also, in many Super Robot Wars games Kouji is rivals with Asuka Langley Soryu. The two of them always but heads. It is amusing, since she would be more liable to antagonize Tetsuya (both of them are two prideful Ace Pilots — Broken Aces, actually — can not stand losing).
Great Mazinger: Again Boss became The Rival of The Hero — in this instance, Tetsuya Tsurugi — in the sequel. Boss could NOT stand Tetsuya, neither his arrogance (pretended arrogance, in fact; but Boss did not know that) nor Jun was infatuated with him. On the other hand, Tetsuya found Boss annoying, and he certainly did not care for Boss stalking Jun and showering her with unwanted attention. Tetsuya's true rival was Kouji, and when Kouji returned to the series, they got a very heated relationship. Kouji wanted to be friends or at least partners, but Tetsuya got very jealous and paranoid. He was an orphan kid with a huge Inferiority Superiority Complex, plenty abandonment issues and no self-esteem whatsoever, and he regarded Kouji like a threat would steal his father from him, take away his reason to exist, and replace him. Geez, he even accused Jun from wanting replacing him with Kouji (in spite of Jun barely knew Kouji and she had spent the whole series trying Tetsuya noticed her). He was ALWAYS arguing, bickering and fighting with Kouji, wether they were discussing tactics or battling the enemy.
UFO Robo Grendizer: Minister Zuril saw The Hero Duke fled like his rival, since he was in love with Rubina, King Vega's daughter, and Rubina was in love with Duke. Nonetheless, Duke regarded him like another Vegan commander he had to defeat.
Mission: Yozakura Family: Sui, an elite spy for the government, serves as this to Taiyo, with the Curb-Stomp Battle Taiyo suffered against him cements Sui as someone for him to beat.
Kai of My Bride is a Mermaid serves as this to Nagasumi, although the anime tends to zig-zag on whether or not it sticks.
Sasuke is this to Naruto himself. Kishimoto actually stated he read up on the archetype in various manga when making him. Sasuke's entire creation was based on the fact that Kishimoto's editor said that Naruto needed a rival. Guess the fangirls should be grateful for this trope.
Then there's Sakura and Ino, though their rivalry has toned down a lot in Shippuden.
During the Chunin Exams, Rock Lee added three other ninjas as his other rivals besides his teammate Neji: Sasuke, Gaara and Naruto.
Also Guy and Kakashi, although this is arguably one-sided and usually Played for Laughs. Rather than knock-down, drag-out fights, it manifests itself in Guy challenging Kakashi to various dares or contests.
A hilarious case where creator Eiichiro Oda sees the Pretty Cure series as a rival due to his young children liking it more than One Piece. He vowed to take it down.
One could argue this for Luffy and Smoker, though it isn't so much as competing over anything as it is Luffy trying not to get caught by Smoker and get thrown into Impel Down.
A better example would be the Eleven Supernovas (a group of eleven rookie pirates, including Luffy and Zoro, with bounties of over 100 million who reached the end of the first half of the Grand Line at the same time) to each other. Eustass Kid and Trafalgar Law in particular are introduced as rivals to Luffy (although, in light of Law's alliance with Luffy, the two of them seem to have a relatively Friendly Rivalry at this point).
There's also Zoro and Mihawk, to the point that Mihawk trained him specifically for the job.
Assassins Jabra and Lucci are fierce rivals, despite both being former associates as members of C9. It's not their fault, however. Lucci has consumed the Zoan Neko Neko no Mi: Leopard Model Devil Fruit (the Cat-Cat Fruit) while Jabra's is the Inu Inu no Mi: Wolf Model or Dog-Dog Fruit. The opposing natures of the two Fruits compel them to oppose each other as a cat and dog would.
Panzer World Galient: After their first battle, Hy Shaltat gets obsessed with defeating Jordy and destroying Galient. He even ignores orders several times in order to have a rematch with Jordy.
Persia, the Magic Fairy: Yuyuko was the best at running and sports, before Persia showed up and took that title. Now that she's no longer the best, she hates Persia and considers her an Arch-Enemy. It's to the point both girls get into a screaming match on Sports Day.
Interestingly enough, in The Pet Girl of Sakurasou, out of the two girls in Sorata's Love Triangle, his little sister Yuuko doesn't see Mashiro as a rival, but rather someone who just needs to be looked after. However, she points at Nanami right after getting on the train, stating that because she's a perfectly normal girl, she would be a romantic threat. Then the train closes its doors and leaves before Yuuko is finished saying what she was going to say.
In The Prince of Tennis both Sanada and Atobe start out as formidable, intimidating opponents. Along the way they earn the main team's respect to a degree, and in the last match, they help the main character regain his memories so he can face his last opponent (who happens to be Sanada's captain).
Ryoga is easily Ranma's foremost rival and closest competitor (as seen here) throughout the series. They've fought several times (excluding minor tussles) and the outcome, while almost always with Ranma being the victor, are usually close. Ranma openly acknowledged Ryoga as his rival, during the "Mark of the Battling God" arc, and has also acknowledged that few could force him to fight seriously, or push him as hard as Ryoga can.
One-time manga character Asuka Saginomiya, "The White Lily", is Kodachi Kuno's rival. She IS Kodachi, just in a different color. She actually manages to top Kodachi in terms of hamming it up by carrying around a large picture frame with lilies tied to her back so she can pose.
Rent-A-Girlfriend: Ruka is Chizuru's rival for Kazuya's affection, even if Chizuru is in denial about it.
Scryed is largely built around the rivalry between brash, free-spirited Kazuma and stoic, duty-obsessed Ryuhou. In other series it's usually The Power of Love that can never be extinguished and can overcome any obstacle; in s-CRY-ed it's Power of Hot-Blooded Macho Rivalry instead. It's a notable example for just how much effort is put into developing their rivalry: at first it's simply because Kazyma and Ryuhou piss each other off, but gradually, even as their viewpoints and personalities change and develop their rivalry simply intensifies over time rather then ever really reconciling, and the series ends on their climactic final battle. Amusingly, in one episode a character with the ability to write a script that everyone must then follow as long as they're in it attempts to have the two reconcile in a friendly sparring match, his story ending in them becoming friends after working through their rivalry. It completely backfires, as Kazuma hates Ryuhou so much that just "fighting until they turn into friends" ISN'T enough for him, and it breaks the script and reality re-asserts itself.
Soul Eater has Ox claiming himself Maka's rival (only academically speaking), and Black Star sees himself as Kid's. Gopher appears to see Maka as his rival for Noah's attention, much to the girl's bewilderment upon first meeting the guy out to kill her with extreme prejudice. He takes the same attitude towards Kid who, like with Black Star, is simply not bothered.
Goodspeed ends up being quite the respectful rival to the main character Shiro from Tailenders. In the end, Goodspeed ends up admitting that he might never beat Shiro after which the later trusts him with bringing Tomoe away from the Terraformer.
In Teasing Master Takagi-san the protagonist has an adorable "war" going with his cute classmate, with each of them trying to get the other to blush and react to their antics. She always wins these little contests.
Viral, as you might guess from his name, serves this role towards Kamina and Simon in Tengen Toppa Gurren Lagann.
To Love Ru: As her name implies, Nemesis serves as this to Momo.
Touch (1981) has Akio Nitta to Kazuya Uesugi and later Tatsuya Uesugi, Isumi Nishimura to Nitta (one-sided) and Takeshi Yoshida to Tatsuya Uesugi, also one-sided.
Ultra Magnus to Optimus Prime in Transformers: Robots in Disguise, as he feels he should have gotten the Matrix. He never turns evil, despite Megatron's best efforts.
Yu-Gi-Oh! GX has Jun Manjoume, a partial Expy of Kaiba, who serves as Judai's rival. Later, he gains a second rival (also a partial Expy of Kaiba, though utilizing different aspects of his personality) in Edo Phoenix. For a few episodes, Hell Kaiser could also count as a rival to both Judai and Sho as well as yet another Kaiba Expy, even using what is at its core a Cyber version of Kaiba's deck.
This continues in Yu-Gi-Oh! ZEXAL. Kaito/Kite is Yuma's rival and might be considered an Expy of Kaiba, but had much darker motives and could not be considered anything more than a Well-Intentioned Extremist until the end of the first season. In fact, he usually considered Astral to be more of a rival to him than Yuma was, although he eventually gains true respect for Yuma. Shark also has IV (Quattro) who started as an Arch-Enemy until the conflict between them was settled, whereupon the two developed a vitriolicFriendly Rivalry.
Yu-Gi-Oh! ARC-V places Reiji in the rival role (as well as having him be another character based on Kaiba), but unlike his predecessors, he never actually acts as a rival to Yuya. Their relationship is largely non-existent, and their conflict is solely based on ideology without them trying to surpass each other. Yuya's true rival is Sawatari, who explicitly refers to him as such and even adopts a similar Duel style, and the two of them display a Friendly Rivalry in the little time they get to Duel each other.
Like ARC-V, Yu-Gi-Oh! VRAINS has Revolver in the rival role, but his antagonistic relationship with Yusaku has nothing to do with actual rivalry, developing from Arch Enemies to Friendly Enemies to Aloof Allies over the course of the show. Unusually for the franchise, Yusaku can't have a rival simply because he Duels for survival instead of competitively or for fun, and while he has a deep respect for Dueling, he never regains his love for it.
Yuuna and the Haunted Hot Springs: Hibari sees herself as one to Sagiri, due to Sagiri being better at pretty much everything compared to her.
The first is Brago, who is called "the demon to beat" by Kiyomaro. Not only is he one of the Four Demon Prodigies, the strongest in the generation that only the adults could defeat, he and his partner, Sherry, are the ones who seek out Gash and Kiyomaro and tell them about the battle in the first place before challenging them. It's only due to Sherry seeing Kiyomaro as a good guy at heart that they didn't have their book burned. As a point of reference for exactly how well Brago fits this trope, he placed second in the battle. To put it more plainly, he and Gash were the last ones standing out of all 100 demons.
Vincent Bari is also noteworthy. A powerful demon on his own, but he didn't have a true motivation in mind before he fought Gash; while he won the battle with them, Gash's willpower intimidated him so much that he decided to spare them until he was that strong. Fast-forward a couple of arcs to when he reappears, having defeated Elzador, another of the Four Prodigies, in a very close battle. That experience gave him willpower to match Gash's, and he's shown to be frighteningly strong. He ultimately decides to pull a Heroic Sacrifice to help Gash and his friends, but his partner praises him, saying that while he wouldn't become the King, he had become someone strong enough to strike even the King.
Yuuka kept them from fighting, but they eventually traded blows during the Venus arc. While Azuki emerged the victor, she later admitted it was only because Yan-Min had held back.