Just like friends casually gathering at a hangout after school, second-year high school student Ishino Kiyoaki's room is visited by popular beauty Minamigawa Shizuku and serious, plain, yet secretly beautiful Futami Sayo, who barge in as if it were their own room at home.
While Ishino and Minamigawa are having sex, Futami is doing his homework at the desk next to them. Hearing their moans, they engage in everyday conversations and argue about who will have sex next.
The three are not in a relationship bound by romantic obligations, but rather a half-hearted one, where they fill gaps in each other's hearts through sex. While neither of them is controlling, they gradually interfere with each other's important matters and slowly come to recognize each other's needs.
Here is a high school boy's ideal sex life.