Mesuneko feromon: Inwai na kuchibiru(2010)

Junko is infatuated with her neighbor, Natsuo. Wanting to know everything about him, she makes it a daily routine to rummage through his trash every morning. If there are few vegetables, she cooks a meal and leaves it outside his door. When Natsuo brings a woman into his room, she thoroughly investigates her. Meanwhile, she fantasizes about having sex with Natsuo and satisfies her sexual desires through masturbation… And then Natsuo brings another woman into his room! This time, it's the girl he's admired since high school. However, Junko finds a large credit card statement in the trash…