Kotani's next project was filming for the made-for DVD release movie, Boys Love,[3] which co-starred Takumi Saito.
In 2007, Kotani took the lead in the theatrical edition of Boys Love, which shared only its title with the 2006 movie, and featured a new story and cast.
Kotani portrayed Aoi Kairu, a young teacher at an all-boys boarding school, who discovers that his new student, Sora Amakami (Atsumi Kanno) is the boy with whom he recently had a sexual encounter.
In 2007, Kotani appeared in the film, Arakure KNIGHT (荒くれＫＮＩＧＨＴ),[4] the live-action adaptation of the 1982 to 1988 manga series, Aratanaru Shobaku by Satosi Yoshida.
Kotani began dating former Morning Musume member Risa Niigaki after they starred in the stage play Absolute Boyfriend in 2013.
TENIMYU: THE PRINCE OF TENNIS MUSICAL SERIES (as Takashi Kawamura) 1999 JUNON SUPER BOY Contest – 5th Place