Since his son, Takumi, divorced when he was five years old, his father, who had been raised by one man, remarried. And the cohabitation with my mother-in-law, Miki begins ... Miki, who is a caretaker, actively tries to shorten the distance with Takumi and even mixed bathing. Takumi who lost to her accepts it ... However, the stimulus to wash the body is too strong for the virgin skill, and it irresistibly explodes. Miki gently wraps him in shame. And that triggered a secret practice with my mother-in-law in the bathroom ...