[FSDSS-524] Because she is a former bully… I played her G-cup big tits insidiously. Record of my domestic training sex – Koyomi Watanuki

The hero of the story, Yuki Yudzuru, was bullied heavily in junior high school, and he ended up becoming an introvert who spends all his time in his room.

Sometime later, his father remarried a woman who already has a daughter, a girl named Koyomi, who is now supposed to be his new stepsister. But to his shock, he discovers that this is the very same girl who used to bully him.

Yudzuru reacts badly to this news, even more, when Koyomi leaves him a very aggressive note: calling him a virgin and telling him to not ever get out of his room.

In view of this Yudzuru decides to look for her weaknesses, and give her some proper revenge.