The music is composed by Elements Garden, and some of the tracks definitely apply, like "CRYSTAL TIME".
The duets between STARISH and HEAVENS members definitely qualify. Prominent examples being "Lasting Oneness" (Masato and Kira) and "Mighty Aura" (Tokiya and Eiji).
Cecil's appearance in the first season. Only Haruka meets him, and he's never mentioned again until he comes back to join the Master Course in the second. It also happens in the main game's routes (except his own): he appears suddenly to give some advice to Haruka, and later disappears for the rest of the route with no explanation.
The second season's ending. Everyone floating in the sky and reaching space.
For some fans of the original game the anime dumbifies the characters, takes away their characterizations and backgrounds and loses the spirit of the original. However, there are also many fans who knew the franchise thanks to the animated series, and who prefer watching the guys interacting with each other rather than engaging in romance with Haruka.
The use of CG in "Maji Love Revolutions". Some find it cheap, others don't mind and consider it makes the song different to the previous endings.
The focus of the anime being given to HEAVENS in Season 2 and 4. While they can work as decent adversaries to the main idols, some don't like how much it expands the cast and especially the antagonism of some HEAVENS members.
Similar to other primarily same-sex franchises such as The iDOLM@STER or BanG Dream!, the UtaPri fanbase broke into pieces when Uta no Princess-sama was revealed not to be an April Fools' Day joke. Many fans felt like it was making an otome franchise into a unisex venture, and thought that the game was dividing up resources to an already bloated lineup of idols in the main series (especially since HEAVENS hadn't shown up in the games and the next visual novel had been in waiting in years). Others think that the girls should be given a chance, since when other franchises experimented with an opposite sex branch it either ended up wildly successful or quietly acknowledged.
Die for Our Ship: Haruka is a girl in an otome game. Three guesses as to what the rabid yaoi fans do to her.
Out of the senpais, Ranmaru and Ai for game fans. Although Reiji became more popular between anime fans after his central episode in Revolutions.
From the fourth season, Eiji, Shion and Van from HEAVENS seem to have grown in popularity.
Of STARISH, Syo has consistently ranked the highest in official popularity polls, such as winning the 2011 Dengeki Girl's Style Otome Awards for Best Character and ranked 3rd overall in the 2015 "Top 20 Characters Otaku Want to Marry" in the Ideal Husband category.
Ethnic Scrappy: How some fans see Cecil and (to a lesser extent) Camus.
Fan Nickname: In the West, a lot of fans took to calling Haruka Hypnotoad both affectiontely and mockingly, due to her unusual eyes.
Plenty. Couplings include Ren/Masato, Natsuki/Shou, Otoya/Tokiya, etc.
The roommates are MUCH more often paired with each other than Haruka in fanworks. Probably helps that Ren/Masato and Natsuki/Shou are also Childhood Friends.
Ren/Masato.
From Season 4, Tokiya/Eiji. Their episode seriously can be seen as a typical shoujo story where Eiji is seen as an angel by Tokiya and Haruka, and with Eiji even giving Tokiya his number.
The whole episode practically involves Tokiya feeling conflicted between staying with STARISH or taking Eiji's offer and joining HEAVENS after seeing how hard the latter works and takes things seriously. But easily, one can interpret it as Tokiya getting interested in HEAVENS because of Eiji.
Haruka. Considering she's the heroine of an otome game, she already has at least six good-looking guys after her; she can be paired with Otoya, Tokiya, Masato, Ren, Syo, Natsuki, Cecil, Hyuuga, Ringo, Reiji, Ranmaru, Camus, Ai... and the list goes on.
Of the boys, Syo has one of the largest shipping pools, nearly rivaling Nanami; he gets shipped with Natsuki, Satsuki, Ai, Nanami, Kaoru, Cecil, Ren, Nagi, and Yamato. And those are only the regularly recurring ones.
Les Yay: Haruka gets REALLY happy when Tomochika visits her. And likewise with Tomo-chan herself; in the anime, her life is pretty much devoted to Haruka's well being.
Nightmare Fuel - Some people find the heroine's eyes to be creepy.◊ Especially since nobody else in the franchise has eyes like that. Fortunately the anime fleshes them out a bit better.
One-Hit Wonder: In universe, Shining Saotome. He had one best-selling single, "Ai yue ni", before retiring and funding Saotome Productions and the academy.
One-Scene Wonder: Seeing a young Raging Ootori and Shining Saotome during their idol days.
Eiichi Ootori was hated for being really creepy towards Haruka along with his Slasher Smile. However, he garnered sympathy and more fans when it was shown that he was like a big brother figure to the rest of his band, and legitimately just wants what's the best for them.
As of the end of Season 4, all of HEAVENS' controversial members have been upgraded to this due to the highlight the better sides of their personalities got. They are still a Broken Base case for some parts of the fandom, but in general they've been well-accepted.
Haruka, for fans of the anime (mainly disliked for her generic personality) and Cecil for both game and anime fandoms.
From HEAVENS, Nagi Mikado is highly disliked by a lot of fans due to his status as being The Fake Cutie and how much of a Jerkass he is with his debut showing him slapping Natsuki's hand away and told him how dare he think they can shake hands. A lot of people really hated the kid in his episode in Season 4 with Natsuki where he taunted Satsuki about Natsuki's Split Personality disorder and was even considering telling the news about it.
Game example. Speaking of Debut, it's considered the worst game of the franchise by some fans, since it focuses more on the senpai (by then who were antagonistic in nature) and the boys' character development instead of their romance with the heroine, and it's generally more angsty than the previous games. This is also why it's the only main game with no fandisc, and why All Star focuses on the seniors' routes instead.
So Bad, It's Good: Some people claim the anime is this. Ironically this is why it's considered one of the best otome game adaptations.
Surprisingly Improved Sequel: After Debut 's disapointment, nobody thought that All Star would become a game as good as the original. Starring the senpais, no less.
◊ Especially since nobody else in the franchise has eyes like that. Fortunately the anime fleshes them out a bit better.
