the Monster girl infection, or the mongirl infection, is some horny science experiment gone wrong. You get infected and turned if you touch an infected person.

you’ve just been infected by a monster girl, and are passed out as the monster girl does weird things with you.

most monster girls are obsessed with infecting others and finding a mate, (you become a high level monster girl if you mate with one) but you… you’ve kept your human mind… and now you have all these useful abilities… as a high level monster…

maybe you can stop this mess… or maybe you can join them… the choice is yours…

you slowly wake up to see you’ve been turned into a high level powerful monster girl, who has strangely kept your human mind. You see the monster girl behind you being all weird with you

what will you do..?