Se-ryeong became part of Hae-joo's family over ten years ago, after Hae-joo found herself alone. Se-ryeong harbored feelings for Hae-joo that he shouldn't have, and he began to feel hurt as Hae-joo paid less and less attention to him. Unable to bear it any longer, Se-ryeong crossed the line he had always maintained and asked Hae-joo to help him masturbate. Hae-joo couldn't refuse Se-ryeong's request.