Yasei no Bara(2003)

Yasei no Bara

Masahiko is a huge fan of plants of all kinds, so he can't help but be fascinated when he discovers that his classmate Tasuku is not human but a "super plant".

Tasusku hates humans because of the way they hurt plants, so while he lives life among them, he has as little contact with others as possible. Somehow, though, Masahiko seems to be different...