Season 1

Sky's father, a respected mafia boss, hires Sun to to be Sky's bodyguard. To maintain a sense of normalcy in his life, Sky demands that Sun pretends to be his cousin to avoid others learning about his father's mafia connections.

After Sun is injured in a brawl at the school, it is Sky's turn to take on the role of caretaker.

Sky plans a special day for Sun to express his gratitude for Sun saving his life. The day is a rare moment of entertainment for Sun who has spent his life serving others.

After witnessing Sun get injured multiple times protecting him, Sky asks for Sun to train him in self-defense. Bank, Sky, and Sun begin preparing for an overnight service trip with their school club.

Sun, Sky, Pitch and Bank begin their service trip. Juno and Toktaeng see the trip as their chance to get closer to Sun and Sky, causing some jealousy to quickly emerge.

As they wrap up their service trip, Bank and Sky both reach a point of frustration with Sun and Pitch, respectively, for their inability to communicate their feelings. Sky threatens to have his father replace Sun as his bodyguard.

Sky's abduction sends Sun, Pitch, and Bank into danger during their rescue attempt.

As Sun recovers in the hospital, he and Sky turn their attention to their next challenge: earning the acceptance of Sky's father.