Min-gyu, Soo-yeon, Young-suk, Wisdom, and Cho-hye go to a three-room pension. Solo Cho Hye-man sleeps in the attic room of Fumijin, and the rest of the friends are couples, so they are assigned a good room. Cho-hye, who is full of heartache, suddenly falls asleep in the attic and has a strangely vivid dream. In a dream, she has a hot sex with friend Suyeon's lover Minkyu. The next day, Cho-hye, who had been in a troubled mind, comes to the attic with another friend Wisdom sleeping. And while they're sleeping while chatting, Min-gyu and three have the same dream of having sex at the same time. And when they wake up, they sense that there is something weird in the attic ...