played this one in jp a while back basically she needs sperm to get magical powers or some bs like that and her og source happened to be her shota brother, but dun dun dun he couldn't produce enough sperm so some other dude shows up and black mails her I don't remember with what specifically and becomes her new semen dispenser and slowly does the classic "his ochin chin is so much better than the other guy!!!!". Its super linear btw you clear a dungeon and than go to ntr guy and repeat I don't think there is a vanilla ending either its basically ntr shoe horned in its more corruption btw it has good art tho