Caelus is an average college student and his older sister, Stelle, is like his mini bodyguard but she actually looks more intimidating than Caelus. Dan Heng, Stelle's friend, is just a few years older than Caelus. He is a successful and quite rich business man, and quite cold hearted as well. He only ever goes out when Stelle invites him to hangouts, though Stelle has a girlfriend so, they only call Dan Heng and Stelle as best friends. But with Caelus's sister, with her girlfriend, on vacation, what could go wrong?