Ouji is a popular junior who is a genius who can do anything. He is also a rival in sales performance at the company, and the protagonist cannot beat him, so she ends up treating Ouji who is getting close to her coldly. One day, at a drinking party after work, the protagonist, who is drunk from the daily fatigue, reveals her hidden desires to the person to whom she should not show her weaknesses ... "Oh... I see, senpai." When she wakes up, Ouji, who seems like a different person, is in front of her...? Obsession x Younger x Doting Training A long night begins with a junior who has changed drastically.