A Peephole (2013) +18

Original title: ノ・ゾ・キ・ア・ナ

Kido Tatsuhiko moved to Tokyo to attend an art school and start his new life. In his new room, there is a small hole in the wall, which he initially ignored. One night, though, he sees a girl named Ikuno Emiru through the peeping hole. She turns out to be a perverted voyeur who ropes him into her peeping fetish... but they both wind up getting more than they bargained for.