In volume 5, Siho and Sey have yet another argument, where Siho finds out that he isn't as far up on Sey's priority list as he thought. When Sey is at the hospital to give Mrs. Kang some change, she runs into him and his mother. It is revealed that Siho's mother suffers from brain damage, caused by a car accident. She and Siho had been hiding in the USA from his father at the time and Siho suspects that his father was behind the accident. In return for going with his father back to Korea, his mother receives medical care. Realizing that she and Siho are both very similar, she takes his hands as she tells him so. How their relationship develops is to be seen in volume 6.