Following the 40th anniversary of the franchise, we have a series based on constellations. However, Kyuranger isn't the first team with that motif. That designation actually goes to, believe it or not, the first Sentai.note Goranger's finale revealed that the team was linked by the constellation, Cassiopeia; even the beginnings of their names in team rank order spells the constellation's namenote Carranger was also based on stars, albeit fake car constellations.
This show also has another allusion to Goranger, and its in its title no less. The Gorangers consisted of five members, whereas the Kyurangers consist of nine members. "Go" is Japanese for five, while "Kyu" is Japanese for nine.
Not to mention that they are introduced with "Nine members assembled, Kyurangers!"note Kyunin sorotte, Kyuranger! much like "Five members assembled, Gorangers!"note Gonin sorotte, Goranger!
And to top it off, the main villain resides in the Crux (cross) system, bringing the Black Cross Fuhrer into mind.
This isn't the first team to have its members hail fromacross the galaxies.note The Flashmen were actually born on Earth. They just grew up on different planets.
This isn't the first season with spaceship themed mecha called Voyagers. Denji Sentai Megaranger also had that.
A partnership between the Gold and Silver members wherein one is a robot and the other is a human/humanoid? It's like Beet and Stag Buster, only with the colors reversed.
Similarly, they join the team as the 6th and 7th members, with the Red, Blue, Yellow, Green, and Black members already present - kind of like the other series that had a pair of Gold and Silver rangers join later, Engine Sentai Goonger.
The first place the Kyurangers eat at on Earth is Cafe Safari, a place that specializes in curry. Kiranger and Captain Marvelous would have been proud.
In the same vein as the Goranger reference above, the team's first Sixth Ranger, Ryu Commander, brings to mind the ORIGINAL Sixth Ranger, DragonRanger - while the colors are different note Dragon Ranger is a green ranger; Ryu Commander is a violet ranger, the motif is the same. Additionally, he starts off with a time limit for how long he can use his powers - kind of like MegaSilver, except unlike MegaSilver, he's able to get rid of the time limit without weakening his power. Coincidentally enough, the episode he debuts in brings to mind last Sentai with a mentor who becomes a violet ranger, mainly due to Naga Ray, Balance, and Champ being elsewhere at the time he transformed.
Ryuteioh has a visor shaped like red pointed stunner sunglasses, similar to Spino Daioh. And in both cases, they're rarely visible due to being covered up by a helmet. Both also have fang-like details around their chins.
Ryu Voyager evokes the same feeling as the Mythical Beast RyuseiOh. Even its intro is similar!
Balance is interested in collecting treasures, and basically has the position of "I'll fly around the universe with the team to get stuff, and might as well destroy a universe spanning evil empire". Sounds like Captain Marvelous and the Gokaigers fight against the Zangyack.
Shou suggests a new name now that there are ten Kyurangers. He calls the team Uchu Sentai Zyurangernote Much like Zyuranger and Zyuohger, it's due to an interpretation of the katakana, as "zyu" and "ju" are treated the same. Thus, it can be read as "Juranger", with "ju" being equivalent to "juu" or 10 in Japanese.. Hami and Spada immediately say that they should stick to Kyuranger.
Speaking of Ohranger, Space 4 sees the start of an arc about seeing the team liberating the already-conquered Earth from the villains, as opposed to simply protecting it from conquest or destruction. Said plot was also used for the last 2 episodes of Ohranger.
Speaking of Ohranger again, the way Kyuren-Oh and Ryutei-Oh combines is very similar to how Ohranger Robo and Red Puncher combines to form Buster Ohranger Robo.
Also for Scorpio, his Karo form's primary color is the exact same color as Takatora's Ride Wear color as both Zangetsu and Zangetsu Shin.
The first 5 Kyurangers to join are Red, Blue, Yellow, Green, and Blacknote Although it's revealed in Space 13 that Stinger was the first Kyuranger that Shou Ronpo encountered - the same colors as Choujuu Sentai Liveman and the core team of Engine Sentai Go-onger, and much like those two seasons, Kyuranger follows the Three Plus Two rule - although ironically, Green and Black (who joined the team after Red and Blue) are already a part of the team at the start (the "Three"), whereas Red and Blue are the "Two" that join the core team this time.
At Space 17, the lunar-powered blue ranger's fighting style is very reminiscent of Geki Blue's. The same episode features a Living Shadow enemy who wouldn't be out of place among the Shadow Line.
Space 18 has DekaRed the only one to call the interdimensional phenomenon a wormhole while everyone else uses "black hole" - this is a specific reference to Power Rangers S.P.D., where the wormhole was the episode title and plot device for their crossover with Power Rangers: Dino Thunder.
Space 21 features the team encountering Tsurugi/Houou Soldier for the first time, who has been asleep for an unknown amount of time, with long hair covering his face, and rising up, initially hostile towards the Kyurangers. If this sounds somewhat familiar, it's because it's very similar to how Burai made his debut.
The Houou Soldier suit is designed with a Zeerust aesthetic, complete with obvious comm device, and even his title is Space Bu-Star.
Space 22 features the debut of Houou Soldier's mecha (Houou Voyager, Houou Station and Houou Base). The first two mecha's combination into Gigant Houou - a rocket-based component flying upward through a second component that forms the arms and main torso armor - is very similar to how parts of the Mega Voyager combine, specifically Rocket Voyager-3 with Saucer Voyager-4.
With the shuffling of field members every episode, one time a formation hearkening back to the classic color scheme set by Himitsu Sentai Gorenger was bound to happen - and it did in Space 23, when Lucky is trying to prove to Tsurugi how The Power of Friendship and teamwork (two of the main tenets upon which Super Sentai stands) are better than his methods.
In Space 36, it's revealed that Lucky received a small lion robot from his father. Hmm...
In Space 37, the red ranger is tied up to a pole in front of the public to be executed by the villain general. Not a first time in Toei's history.
In Space 38, Raptor, Naga, Hammie and Garu start using fighting styles based on animal Kyutama in the same vein as the Gekirangers. Helps that the Kyulin Temple set was used in Gekiranger as well.
Space 40 is basically a homage to Goranger's infamous baseball episode, complete with baseball themed Monster of the Week and Yellow winning the game. Even the Cassiopeia Kyutama allowed them to do Kyuranger Hurricane, which make sense as Cassiopeia was the naming joke for the Gorangers.
Space 41 has the heroes facing Hell's Gate. That was the name of the prison cell that housed the worst criminals back in Mirai Sentai Timeranger.
Also note that Southern King's costume is a direct repaint of Black Cross King.
Space 43 has the rangers destroy a monster by using the earlier three giant robots using the fourth one as a cannon just like Dekaranger did in their episode 43.
In Space 45, Professor Anton turns the civilians into mooks by putting masks on them. He must've gotten the idea from Enter.
◊ such as Five Yellow.
