Inferior Genes and Ponytails
Its RPGM but gameplay is different its mostly a menu based system. But story / concept wise its probably the closest thing I know. Corruption arc is more realistic / more build up (Kotoko is just a straight up slut lets face it, talk to an old jeezer twice and hes balls deep in her ass) Gameplay isnt stellar but otherwise its quite good especially for that specific Kotoko fetish.
It starts slow but she really goes exponential..
Also Title is fantastic imo ahah
Scars of Summer
Be warned this one is NTR, but I highly recommend it. One of the best games out there. (NTR is quite soul crushing, many routes, much replayability, nice system, great writing)