Shounen ai/yaoi MUST READ

Lin Tian-Yu is the president of the student council and the disciplinary committee, and Xu Ze is a high school freshman. During a regular classroom inspection, Tian-Yu finds Xu Ze sleeping during morning self-study and reprimands him. Their seemingly ordinary encounter ends up changing the lives of the two greatly.

After a car accident, Taemin finds himself in the body of Siwon, a victim of bullying at school. No longer a pushover, he starts standing up for himself but then meets Woojin, an old friend from the past. Somehow, Woojin immediately picks up Taemin's 'scent' from Siwon.