The beautiful stepmother pampers her husband’s son.

Accidentally slapping her son because of her, the stepmother apologized by not being better. Since his father remarried to Yu, Ryota had another stepmother. Ryota is at the age of learning about "physiology", his stepmother is an extremely beautiful and charming person, her mother's smile seems to want to suck his soul away. However, Yu is his father's wife, so Ryota gave up, knowing that his feelings would not be reciprocated. Suddenly, his opportunity appeared. His father will be on a business trip for three days, Ryota won't miss this one chance of his own! He immediately attacked Yu to take her! But Yu resisted strongly and slapped him. Knowing that he was overreacting, Yu went to Ryota's room that night to make up with him. Ryota will agree to forgive Yu on the condition that she close her eyes. And he used this opportunity to take her over again! But unlike last time, this time Yu resisted weaker, seemingly letting Ryota take over her body. And the feeling of happiness that Ryota brought quickly conquered her. Even though she knew this was wrong, Yu couldn't stop. She wanted to be with Ryota even more. The two kept being together while her father was on a business trip, and even after he returned, they continued their forbidden relationship. The costly apology from the stepmother.