Wei Qian (played by Qiu Yuchen) lost his parents at a young age and shouldered the responsibility of the family. In addition to raising his sister Wei Lili (played by Lin Siting), he also accidentally adopted his younger brother Wei Zhiyuan (played by Huang Hongxuan). For his younger siblings, Wei Qian desperately worked illegally to make money. Fortunately, his good brother Sanpang (played by Kim Jae-hoon) who grew up with him pulled him back on track. When life gradually got back on track, Xiaoyuan admitted that the person he liked was his brother, and then forcibly kissed Wei Qian. Wei Qian sent Xiaoyuan abroad in a rage, and felt that something seemed to be missing in his heart. Can the two people who are not related by blood only be family members and brothers in the end? Or can they cross that taboo line and become lovers? The play is adapted from the BL novel "Big Brother" by Priest, a Jinjiang literature author.