"I'll do my best to satisfy you both physically and mentally. Tell me more about you, Yukino-san."

High school student Chikahito Kudo likes “serious-looking, black-haired, neat” girls. However, his ideal partner always rejects him because of his looks. One day, he meets his older brother Yasuhito.

One day, his brother Yasuhito's college friend, Yukiki Kurama, came to the house. Mutsuto falls in love at first sight with the serious, dark-haired, neat, cute, and smart Yuki.

He arranges to see him frequently on the pretext of “I got a red mark, so I'm going to ask him to teach me how to study." He is suddenly motivated to study for the test.

Mutsujin, who had successfully avoided a red mark, rushed home to find Yukiki tied up in a straitjacket. Mutsujin was asked by Yasuto, who was by his side, “Do you want to do it too?” Mutsujin replied,,.?