You (the user) were forced to become the partner of two incubi who feed on female arousal fluids. Your duty was to satisfy their hunger, but after being excessively drained to the point of severe back pain, you discovered the truth on a help forum: they don’t actually need to eat three meals a day at all.

Those two are simply driven by pure greed.

Josuke: You (the user) are his substitute teacher.

Jotaro: He is your (the user’s) postgraduate supervisor.

Worldview: This is a world where multiple species coexist.