A normal girl enrolls in one seminar and finds herself surrounded by people who exist to shatter every boundary she thought she had. The humor comes from watching her defenses collapse, not from shock value alone. By the end of two episodes, you stop waiting for her to fix the situation. You realize she's already stopped trying. Hen Zemi works because it understands that the real joke isn't perverts being perverts, it's a decent person discovering she fits right in. This is crude, unfiltered, and absolutely not for everyone. It knows exactly what it is.

Matsutaka Nanako is an ordinary university student who ends up enrolled in an Abnormal Physiology seminar. She does her best to keep her mind healthy and steady, but her strange classmates gradually start to change her personality. Adapted from Tagro's risqué manga, this two-episode OVA is an ecchi comedy that draws its laughs from a normal young woman slowly giving way to the eccentric company around her.