Takumi's parents divorced when he was only 5 years old. Recently, his father remarried and he gained a stepmother. Miki is a gentle woman who cares and worries about Takumi, making him feel the warmth of a mother's love. Wanting to be close to Takumi, Miki came up with the idea of... bathing together! Being a young man, the sight of a woman's body quickly aroused Takumi's penis! Miki took the initiative to bathe Takumi and when she touched his penis, he ejaculated immediately! Feeling embarrassed about ejaculating too soon, Takumi searched online for treatment. Miki accidentally found out about this and wanted to help Takumi feel confident in himself by teaching him more about sex. With this in mind, Miki continued to bathe with Takumi, but this time she actively let him touch her breasts, vagina, suck his penis, and have sex with her! From then on, Takumi was always guided by his stepmother to learn more about sex. Being smart, Takumi quickly understood everything, making Miki unable to forget his penis. And the happy life of the three-person family continued in this way...