Koharu Makitani is suspected of cheating on her boyfriend, Tomoaki Kuniyoshi.
When she tries to calm him down, he becomes enraged and almost hits her.
At that moment, he spontaneously started to play “Judo” which he was taught in his childhood...? What happened?
Koharu, who usually has a calm personality, puts a stranglehold on Tomoaki's body,
Tomoaki's body faints in agony, but she can't stand it any longer, and her body undergoes naughty changes...!

The boyfriend who loves her so much that he attempts to turn into a yandere, and the girlfriend who is a martial artist(?).... and her,
A domestic hard love between a boyfriend who loves her too much and a martial(?) woman!