Qianyue, a high school girl, is a nervous girl who likes to solve problems with violence. She lived in the house left by her adoptive father with her younger brother Xiaowu, who was in elementary school, and lived a life that was no different from ordinary people. Until after school, Qianyue was accidentally involved in the battle between the monster hunter girl Nightingio and the monster. In the chaos, Qianyue accidentally awakened her identity as a monster. She wanted to fool around, but she didn't expect that the nightingio would also appear in her school the next day. Since then, everything around Qianyue has changed dramatically. In order to protect herself and her family, Qianyue was forced to start her own battle in the gap between the forces of hunters and monsters. The mystery of Qianyue's real identity was slowly revealed as the plot developed.