Sayonara, Zetsubou-Sensei

After confiding in his latest despairs to Ms. Arai, she asks Nozomu to visit one of his students who hasn't shown up to school — Kiri Komori, a hikikomori. When he arrives at her house, he meets Kafuka, who joins him in his attempt to reform Kiri, even though her attitude causes her to misunderstand (and complicate) the situation. In the end Kiri goes to school but decides to be a hikikomori there. The next day, Nozomu notes that another of his students, Matoi Tsunetsuki, didn't show up that day. Ms. Arai brings Nozomu to the counseling room, where she explains Matoi's obsessive-stalker tendencies to Nozomu. That night, he attempts to dissuade her from bothering her last boyfriend; however, his strategy — suicide as the ultimate form of love — backfires on him once he tells Matoi he will kill himself with her if she wishes, as he has offered in the past. This turned him into Matoi's latest object of affection. (Source: Wikipedia)