Kim Jiwoo is in her junior year of high school and has recently moved to Ssangmundong, a street filled with people who treat each other like a family. On the very first day she encounters the resident angel Soobin and resident devil Yeonjun, along with Beomgyu, Taehyun and Huening Kai. What will happen when these 6 people become Classmates? Will the boys welcome Jiwoo in their group? Follow Jiwoo and TXT as they navigate through school, college and witness their life in this coming of age story. Inspired by River runs through it and reply 1988.