Mi-ra, a woman with violent and boyish personality. Jeong-seok, a timid man who finds Mi-ra's violence attractive. Jeong-seok is a visual but his every action and his slouched shoulders make him look really timid. Do opposites really attract? The two people were drawn to each other's different charms. Whenever they're having an intercourse, Mi-ra led everything, and she makes aggressive demands like scribbling on her body or swearing on her. However, the timid man's standard has not changed, and Mi-ra says goodbye to Jeong-seok. He happened to meet Tae-hee by chance. Tae-hee is a hardcore master! She is an instructor who runs a private tutoring center with Seong-ho. Jeong-seok learns the essence of being hardcore from them and begins to straighten his slouched shoulders..