My stepmother was cheated on ~Several years after my father's death, I've finally reached the age to get married~ Mizuno Asahi VENU-419

Kiyotaka's father passed away five years ago, and he has lived with his young and beautiful mother, Asahi ever since. Kiyotaka, who has just entered university, unexpectedly discovers while organizing his books that Asahi is not his biological mother. Shocked and initially despondent, Kiyotaka develops unusual feelings for Asahi…