Han Tae-joo, the heir of TB Group, is under the protection of Kang-gook who has been his best friend for fifteen years. The two share a master-servant relationship, with Kang-gook acting as Han Tae-joo's bodyguard. As they grow up, Kang-gook slowly realizes that he likes Han Tae-joo as more than friends, but realises that he has to keep it to himself. He cannot take his eyes off of Han Tae-joo, but neither can he get as close to him as he wants. Han Tae-joo, on the other hand, is a player who has had several girlfriends in the past, and who is confident and assertive. He knows all of Kang Gook's weaknesses, and enjoys pressing his buttons. The two friends share an unnaturally close friendship, often blurring the lines between friends and something more. Kang Gook often looks at Han Tae-joo with lingering looks of longing, and they share many charged moments of unresolved sexual tension. This state of affairs changes when Choi Hye-mi, a new female student, joins their high school and shows interest in Kang-gook. Han Tae-joo is forced to confront his feelings for Kang Gook. Throughout the story, Kang Gook tries to keep Han Tae-joo at arm's length. This leads to several occasions where Han Tae-joo, who is having none of it, pushes Kang Gook's boundaries.
