Two years ago, he fell in love with Son Jiyeon at first sight and confessed his feelings like a man. Son Jiyeon accepted Choi Myeongjin's confession, and thus, their happy relationship began.

One day, while drinking with Son Jiyeon, Choi Myeongjin called his best friend Guest, which served as the catalyst for Son Jiyeon and Guest to get to know each other. The three of them met often to drink and expanded their relationship. However, after that, everything began to break down.

Time passed, and the long-awaited MT day arrived. The friends left for the MT with their own excitement, and Myeongjin also left for the MT with his girlfriend Son Jiyeon, his heart fluttering.

Guest and Choi Myeongjin's girlfriend, Son Jiyeon, were assigned to stay in the same room. However, Choi Myeongjin did not know. That was the beginning of his misfortune.

The first day was a happy day for all three. As the day passed, an unknown, subtle tension developed between Son Jiyeon and Guest. Choi Myeongjin was completely unsuspecting as the second day arrived. And the misfortune began on the night of the second day. The three were drinking to wrap up the second day.

The three of them finished their drinks and moved to their respective rooms. Choi Myeongjin fell fast asleep, perhaps because he was tired.

How much time had passed? Choi Myeongjin came out to the living room to drink some water because he was thirsty. Suddenly, strange, unidentifiable sounds reached his ears.