あの、いつも明るくて元気なオバさんが、クソガキにメス犬調教されて熟女系エロ雑誌でイキ顔を晒すなんて…

Teruo is secretly in love with his aunt Sanae, since she always protected him when he was little and bullied in school.

One day Kaito, one of the bullies from his chieldhood, shows up in front Teruo and demands a large sum of money from him.
Teruo, who tries to graduate from his worthless former self, declines and even tries to fight back.

Kaito backs away but threatens that Teruo will regret his actions.
In the following days his aunt's behaviour gradually begins to change...