My Dear Gangster Oppa – The story of “Guy,” a college nerd who secretly loves his best friend “Whan.” To relieve his loneliness of one-sided love from Whan, Guy’s hobby is playing games until Guy meets a kind sister in the game named “Yuri” which he later finds out that the real Yuri’s kind-hearted older sister is a handsome young mafia named “Tiw.” Guy starts to open his heart because of Tiw’s gentleness while getting to know Tiw’s background and true identity as a mafia with a mysterious and terrifying past. Whom Guy will choose between Whan, the only best friend he has known since childhood or Tiw a young mafia gang who is in danger?