Ryota lives alone with his Mother Kimijima Mio in a very humble small apartment. They struggle but they live happily.
One day, his life goes crashing down when he returns home and discovers his beloved Mom having sex with his best friend Yuya.
Ryota feels betrayed and pissed off and he wanders aimlessly the city to find himself in front of Yuya’s house, to contemplate their very big and rich house. Then suddenly he bumps into Yuya’s mom: Shiraki Yuko.