It's from a game set in an alternate universe where Yamada(who now has a face) has to milk the nurses' breasts while they have to jerk his dick off every 3 hours (while his sperm has some property that can suppress this disease). Seems to me that this alternate universe has changed the designs a lot. Tachibana now resembles Mia. Kurokawa looks like Kiritani. Yamaguchi and Amamiya are semi recognizable. Ootsuka has some weird eyepatch thing.
TLDR: Yamada has to milk the nurses while they have to milk his dick.
