Marigold Dilemma

Kwon Ga-Eul, the younger brother who always lets someone with a similar face to his brother into his room. The only one who has not been able to enter his room is his step-brother Seo Yi-Sol who lives with him. "Can you sleep with me? If you don't want to, then don't cross the line." It has been 6 years since Ga-Eul was unable to cross the line drawn by him, and Yi-Sol wants to cross that line. (Source: Mr.Blue, translated)