The main character, Kajiyama Nagito, has been popular with girls since he was a child, but in the winter of his second year of junior high school, he was stabbed in the abdomen with a kitchen knife for refusing a confession from a yandere girl, and ended up wandering between life and death.
Nagito managed to survive, but he became afraid of being popular with girls, and after entering high school, he started to aim to be a friend character instead of a hero.
He was able to make Machida Yoshiharu, a friend in the same class as him, the main character, and while acting as a friend character himself, he succeeded in getting Yoshiharu and a girl to get together with his pride in his comic skills and his good looks.
One day, however, Sagisaka Ruria, the beautiful girl he had hooked up with Machida, appears in front of Nagito and asks him to make her the “losing heroine”