|Anime||Rosario + Vampire Capu2 Episode 10|
|Race||Incubus (originally Transformer Bat)|
|Hair Color||Deep Blue|
|Voice Actor||Takehito Koyasu (Japanese)|
Jerry Jewell (English)
Kōtarō Ijūin (伊集院 光太郎 Ijūin Kōtarō) was a transfer student at Yokai Academy who only appears in Rosario+Vampire Capu2 Episode 10. Moments later, he is revealed to be Kōmori Nazo in disguised, the narrator of Rosario+Vampire and Kokoa Shuzen's bat servant.
Rosario+Vampire Capu2EditWhen Kōtarō first arrived at the academy and being introduced he started putting all the girls under his spell, "Je t'aime" (French for "I love you") including Tsukune's friends, Ms. Nekonome and Ruby Tōjō. Ijuuin sees Kokoa Shuzen who is looking for her bat, Kō, but when she met Kōtarō she believed him to be gross. Kōtarō saw Kokoa to be a great victim. After Tsukune Aono become suspicious about this and told Ginei Morioka what the transfer student is doing, Kōtarō put Gin under his spell (acting like a puppy) leaving Tsukune to solve this problem all by himself. Kōtarō thinks to himself about how he can control the whole school with his power of hypnosis, laughing aloud.
In the school auditorium filled with girls, Kōtarō is singing on the stage with Tsukune Aono's friends as background singers. Tsukune arrives telling Kōtarō to stop but is halted by Ruby Tōjō. Kokoa arrives and tells Kōtarō to stop singing as it annoys her. Kōtarō tries to put Kokoa under his spell and imagines Kokoa in a wedding dress, telling him she loves him. Kōtarō gives himself away when called Kokoa Shuzen by "Kokoa-sama" knowing that's what Kou calls her. As Moka Akashiya is able to move where Kokoa is to save her while being controlled by Kōtarō, Tsukune tries to jump Kōtarō but misses and lands on Moka and Kokoa. Kōtarō then realizes that Tsukune removed Moka's Rosario releasing Inner Moka seeing he's in be trouble now. As Kōtarō tried to put the two vampire under his spell, Moka together with Kokoa countered attack with a double kick and defeated Kōtarō. With that, Kōtarō changes back into Kou and with his broken fang releasing his spell of controlling all the girls then returning back as Kokoa's servant.
- Charm: Kōtarō is able to charm a lot of girls when they first look at him.
- Allure: Kōtarō is able to use this ability to let people's guards down when he says "Je t'aime". Anybody subjected to this ability will fall in love with him and see him as their master, fawning over him and obeying his every command as he charmed every female regardless of sexuality (minus Inner Moka) and straight male Ginei. The gender and possibly sexuality do not matter. This ability is hinted to be lost at the end of episode 10 when his fang, which glitters whenever he uses the ability, breaks. However, it is unknown if his second fang can do the same, or if said fang can grow back, as this was the one and only episode arc for Kou. This ability is similar to Kurumu Kurono (who is a succubus) who has the ability to allure and seduce every male.