Bijukubo  

미숙모, 美熟母

Yohei lives with his mother, kaho, and cousin, fumika. however, one day, kaho reveals to yohei that she is actually his father's older sister, and his real mother passed away long ago. this shocks yohei, but he starts seeing kaho as a woman rather than his mother. a few days later, ikue moves into the house next door. when ikue first meets yohei, she breaks down in tears and kaho faints. ikue tells them that she is related to yohei's real mother and wants to adopt him as her own child. kaho and fumika reject this proposal, leading to their new lifestyle becoming more lewd and erotic.