At the beginning of the new semester, Gu Huai was pleasantly surprised to find that his childhood friend Mu Jin, whom he had not seen for many years, entered the same school as him and slept in the upper bunk of his. But what makes him at a loss is that the other person has become very different from his impression of him. This change makes him not sure how to treat this former little brother...
Bizarrely, deaths have occurred in the school one after another since the beginning of the term. What all the dead people have in common is that they all lived in the dormitory 602 where he lives now...