- I Have No Son!: In season 4, he disowns Masato due to the latter's wish to continue his idol activities. However, he is shown to accept his job as an idol and even watches the SSS decisive concert on television.
- Succession Crisis: Masatos uncle was actually in the position to take over the business instead of Masaomi, but he ran away from it, causing Masaomi to take over the job.
The alter-ego of Natsuki. Is a genius when comes to composing music, although incredibly violent and rumoured to have put 50,000 people in the hospital.
CV: Kissho Taniyama
- But Now I Must Go: In Natsuki's route in ''Repeat', he dissapears after Haruka assures him she'll always love Natsuki and that she'll never hurt him. Natsuki's personality from that point gets a bit more teasing and seductive, though.
- Chivalrous Pervert: Constantly makes passes at Haruka in the games, but he's obviously screwing around.
- Curtains Match the Window: Just like Natsuki, in the games. In the anime it's switched to green.
- Flanderization: To an extent in the anime, where his violent trait is the only notable thing about his character. The reason of his existence is never explained either.
- Hidden Depths: In Natsuki's route in Repeat, it's revealed his reason for existing is protecting Natsuki from getting emotionally hurt, as he got his heart broken by his violin teacher when he was younger.
Tokiya's older twin brother, Hayato is an eccentric, energetic idol. Haruka idolizes him and hopes that he'll sing a song she wrote one day.
CV: Mamoru Miyano
- Catchphrase: "OHA♪YAHHO~!", used at the beginning of his variety show.
- Image Song: Gets one in the anime, it's "Seiten☆OHA♪YAHHO".
- Keet: So hard, and to such exclusivity, that his actual self, stoic loner Tokiya grew to really really despise doing the Hayato act. Hence, his enrolling in Saotome Academy to try for a career as his real self.
- Polar Opposite Twins: Subverted, since he and Tokiya are actually one and the same.
CV: Yuuki Kaji
- Adapted Out: So far.
- Averted with the OVA, where he gets a mention and appears in a flashback with Syo. He also says he wants to invite over Kaoru sometime.Also mentioned by Syo in episode 5 of season 3, and showed in another flashback.
- Always Identical Twins: He and Syo look exactly alike; the only differences being Kaoru is taller, their bangs part to different sides, and Kaoru doesn't have pierced ears.
- Attractive Bent-Gender: He looks just like Syo, if Syo looks good as a girl, Kaoru looks good as a girl.
- Big Brother Attraction: Could be taken as this; Kaoru firmly believes that he's the only one capable of making Syo happy.
- Big Brother Worship: Looks up to Syo a little too seriously.
- Big Little Brother: Though the younger brother, has a couple of inches on Syo.
- Kaoru is also extremely protective of Syo, with how he acts around him, one could easily forget Kaoru's the younger brother.
- Likes Older Women: Revealed to be dating an older woman in All Star After Secret.
- Sibling Yin-Yang: While Syo wants to become an idol, Kaoru is aiming to become a doctor. Also, Syo is more energetic while Kaoru is more responsible.
It was later revealed that she lost her memories and somehow ended up at Agnapolis, where she became the king's lover and gave birth to Cecil.
- Adapted Out: She does not appear nor is mentioned in the anime series.
Haruka's grandmother taught Haruka how to play the piano and helped foster her love of music. She is shown to be one of Haruka's greatest supporters and always looks forward to listening to Haruka's composed pieces.
CV: Hikari Yono
- No Name Given: He is always referred to as hakase (professor or doctor).
The manager of HE★VENS and Raging Entertainment, as well as Eiichi and Eiji's father. Was Saotome's rival during their idol days, and their rivalry continued after both established their own idol agencies.
CV: Tomokazu Sugita
- Abusive Parents: To Eiichi more so than Eiji in Season 4 where he has no problem degrading him and even angrily shaking him when he defied him.
- Cigar Chomper
- Evil Counterpart: To Shining. Probably the reason they hired Sugita for this role is because his Norio Wakamoto impression is awesome.
- Glory Days: In his idol days, he sold 19 million copies of his single, Love is Dead. Season 4, he is shown to still be bitter and resentful towards Shining Saotome who outdone him.
- Man in White: In his youth, he wore white pants and a white coat with fur trim. A contrast to Shining Saotome who wore black. Can also be seen as symbolism as white is the color that represents death in Japan, and the song he performed was called "Love is Dead".
- Nice Hat
- Pretty in Mink: The white coat he wore in his Glory Days.
- Record Producer
- Sinister Shades
- The Rival: To Shining Saotome.
- Took a Level in Jerkass: In Season 2, Raging Ootori was introduced as Shining Saotome's rival who was harsh and intimidating, yet kept his word and played fair. Likewise, he seemed to have humbled after getting hit by the Happy Pulse. Season 3, he was still over-the-top like Shining Saotome, but he was more agreeable and even teamed up with him. Come Season 4, and he's obsessed with crushing the competition as well as appearing more bitter and obsessed with a past failure.