According to the biggest dating website's research, teacher is among the top five professions most likely to cheat, and their students' parents are among the people whom they cheat with. Xiao-xiao, who has mild ADHD, is the troublemaker in her class. But she has her own trouble - her mother Wei-fang and her homeroom teacher, Paul, have started a romantic relationship as a result of discussing her ADHD conditions.
When her mother gets sick, 13-year-old Fen moves back to Taiwan, where she struggles to fit in amid the 2003 SARS epidemic.