Adorkable: Keiichi is so quirky and awkward you really can't not love him.
Diagnosed by the Audience: Social skills aren't Keiichi Shimizu's strong suit, and his constant tendency to fall asleep might make one worried about him having narcolepsy.
Hino: Despite this being a series where Hino can end up with anyone, some yaoi fangirls will turn her into a rich bitch that only cares about about herself and the guy she's dating (which is usually Kaji who is also portrayed as a terrible person). And this comes from the people who support Tsuchira/Tsukimori.
Tsuchira: For anyone who would rather have Hino with someone else, Tsuchira is usually portrayed as a more extreme version of the clingy jealous guy who constantly tries to beat Kahoko into submission.
Kaji: He has it just as bad as Hino. While in most stories, he's not portrayed as a jerk that just wants Hino for sex, but in the stories where Hino cheats on whomever she's with to be with him, he's usually portrayed as a jerk jock instead of the considerate guy that generally cares for most of his rivals (except for Yunoki).
Ensemble Dark Horse: Kazuki is generally well liked in the fandom for his upbeat personality and not being either a jerk or possessive toward Kahoko at one point.
Kazuki/Kahoko is surprisingly popular along with the Official Couple: Len/Kahoko. This might have to do with the fact that Kazuki is the first guy that falls for Kahoko and openly admits it relatively early. He and Kahoko also hang out relatively often without Kahoko getting nervous around him like she does around the other guys and in the anime are the first to get awkward moments with the Almost Kiss scene coming to mind.
Shimizu and Fuyuumi mainly for being around the same age and being paired up often in the series.
Suspiciously Similar Song: Brand New Breeze (the Opening for Primo Passo) sounds very similar to Elgar's Salut d'Amour. The composer is highly influenced by Elgar, anyway
Kahoko at certain points in both the anime and the manga mainly during the third performance.
Hihara when going through his Break the Cutie phase around the same time as Kahoko ironically.
Fuyuumi as well, who gets picked on by her upperclassmen who are jealous of her playing skills. It doesn't help that she doesn't rank high in the competitions, and some random guys tell Shimizu and her that the freshmen should drop out if they suck so much.
Takuto did go through a difficult period over sustaining a Career-Ending Injury, but he's since found a new way to pursue sports and doesn't think too much of it. It's really Sōji who indirectly caused it who angsts about his disability more than he himself does.
Otone, who over the years watches all his school friends move out of his campus, can't follow them and ends up in utter loneliness, but is still all fluffy and innocent when the heroes find him.
Anvilicious: Despite the generally optimistic tone, the game offers unflinching looks into the realities of the music industry and pushes the moral that elitism and pursuit of monetary success and fame at the expense of genuine enjoyment of performing and the welfare of performers is wrong.
Cliché Storm: Spirited, ambitious heroine leads budding orchestra against various challenges and adversity to become the best, making True Companions along the way. Not the most original plot around, especially for a game released in 2021.
Fanfic Fuel: Exactly what kind of person was Izumi Mikado like? What did he look like, for starters?
Good Bad Bugs: Occasionally, sprite errors during play cause characters to play their instruments behind their backs.
Akira & Seiji are one of the most common non-heroine ships, if not the most period, due to their complex rivalry-friendship explored in great detail in their arc.
The heroine herself has some rather homoerotic implications with Rei. The latter's first scene features the heroine accidentally treated to her Marshmallow Hell, then she admits to wanting to get into Starlight out of liking the heroine rather than any of the male orchestra members. Some of their interactions are oddly romantic, and Rei calls the heroine cute multiple times.
Lynn & Ryūsei make up a two-man idol unit, have contrasting and conflicting personalities and worldviews, but stay inseparably close nonetheless. They even share a memento (a button) from their first concert.
Ukiha & Gen'ichirō get in on this almost from the get-go, having a Mistress and Servant Boy dynamic with the latter's showing Undying Loyalty to the former out of gratitude and the former's genuine kindness for the latter despite ordering him around. The whole thing comes off as one-sided pining from Gen'ichirō's side and even Ukiha's betrayal of him reads like a breakup. The beginning of Sapporo arc only serves to strengthen this ship.
The fact they're adoptive brothers aside, Sakuya and Kei are posed rather suggestively on the cover of an issue of B's Log.
Incest Yay Shipping: Kei has been shipped with adoptive older brother Sakuya, though to be fair, they're adoptive.
Ukiha betrays the heroes, falls to the dark side and dumps Gen'ichirō rather cruelly, but given the ordeal he's put through beforehand, it's impossible to truly oppose him.
Kei is an all-around prick, but once his backstory is revealed, one has got to feel sorry for him. He and Sakuya studied from a mentor who instilled positive ideals in them and built a proto-StaOke, but when the reality of the music industry hit them and their orchestra, he had to take a level in jerkass, boot the mentor off for incompetence and turn Granz into what it is now. He also ended up losing Sakuya, the last person he was close to.
Mind Game Ship: Ukiha has been shipped with Taiga even though the latter is deeply exploitative towards the former, has no sympathy for the former's situation, harasses him constantly until he gives in and only sees him as a target to be conquered.
Scrappy Mechanic: That this game is a Card Battle Game and raising sim rather than a rhythm game as expected of its music-related subject matter or a visual novel seems to be this for many.
Miyazaki arc in general especially the fact that, unlike Ouroboros, the amusement park doesn't get saved.
Kyoto arc is just one big Break the Cutie for Ukiha: his family is disgraced and he has to live with the consequences, which means he may have to give up music one day, and another student from his school keeps pestering him into joining a brutal agency trying to make money and fame off his family name which he ends up actually joining in the end, betraying everyone else and ending his long friendship with Gen'ichirō.
The implication that his father Izumi was either Driven to Suicide or died from sheer trauma.
The Woobie: A fair number of arcs produce these, each one bigger than the one before.
Rei; formerly section leader for a highly demanding and predatory orchestra whose concertmaster is an elitist jackass who cruelly kicked her out without a second thought just for taking one day off from all the stress, even though she was a section leader.
Sōji; used to be a promising hornist until he unwittingly destroys both his and his friend's pursuits of their respective careers and is guilt-ridden about it, was an outgoing kid before becoming shy and cynical with low self-esteem, and finally seeing the theme park of so many people's childhood where he works part-time at about to get demolished out of corporate greed.
Otone; just the fact he's the only student left on his campus is enough, let alone how overjoyed he is when the orchestra befriends him and saves him from loneliness.
The entire Mikado family; due to Izumi's career-ending controversy, the family falls on hard times, loses all its students, and the ensuing disastrous effects fall squarely on his son Ukiha. Ukiha himself turns out to be a Stepford Smiler who helplessly watches his once glorious family descend into ruin, but decides he can do nothing and just resigns himself to fate. Without even getting to Taiga's persistent harassment of him into joining a predatory agency who wants to capitalize off his family name, there's an air of perpetual sadness about him that one can hardly help feeling sorry for him.
Gen'ichirō. Devoted to someone extending kindness to him only to bear the brunt of his betrayal.
on the cover of an issue of B's Log.