Character	Aoi Kouya
Appearance	Risou no Kareshitachi
Media	Japanese Manga
Type	Yandere
Love Interest	Naho Horisawa

Aoi Kouya is the student council president of the school which Naho Horisawa is studying at. Good-looking, kind-hearted and smart, he is the perfect student that every girl admires. Incidentally, he also saved Naho from a train molester during her commute to school, which started off their friendship.

SPOILERS AND PERSONAL OPINION

While initially appearing kind and understanding, Aoi quickly changes his demeanor upon realizing that Naho may be taken away by Hayato, who is Naho’s crush. He started flooding Naho with text messages, and started spreading false rumors that Naho and him were going out. Even as Naho make things clear and rejects him, he does not accept the answer. It escalates to Aoi paying uninvited visit to Naho’s home and introducing himself as Naho’s boyfriend to her mother. Ultimately, he turned violent and severely injures Hayato, and even tried to strangle Naho to “clean” her. Luckily, he was stopped, and ended up disappearing from Naho’s life thereafter.

As this is a one-shot manga, the character development of Aoi is extremely fast, and his behavioral changes occurs in a matter of pages. Nonetheless, this character fits the bill of a yandere through and through, and gets increasingly creepy towards the end of the story.