Min-joo and Dong-hyeok have been best friends since they were kids. But one night, everything changed. Dong-hyeok thought he finally had a girlfriend after being single for so long, but it turned out to be all in his head. Min-joo was the one who brought him back to reality—and confessed that she had feelings for him. That confession led to them spending the night together, turning their friendship into something unexpected. While Dong-hyeok tries to figure out his feelings, Min-joo’s roommate, Ji-hye, suddenly gets close to him, making things even more complicated.