Min-wook loves his roommate friend Yeongsu's older sister, Sujin. However, Sujin will soon marry a man who meets the condition. I try to hide my heart and wish my sister happiness, When she sees her divorced a few months later, the old feelings come back to life. Soo-jin, who is divorced, will stay in her sister's house for the time being. Min-wook and Su-jin, who have been in one house, are now trying to confirm their love for each other...

"Sorry! It was because I was lonely."