My parents are going on a trip together, leaving me home alone. Freed from my mother's constant fuss, I'm looking forward to enjoying the freedom of eating whatever I want, playing games, and masturbating whenever and wherever I want. But then my mother's best friend, Mei, gets into a fight with her husband and runs away from home, and we unexpectedly start living together. After a while, Mei finds out that I'm a prematurely ejaculating masochist. Then, with a smile on her face, she looks at me, as if she's found prey...