Five years ago, on a full-moon night, Shen Siwei got drunk and entered the wrong room, spending a passionate night with Pei Xingye and giving birth to a son, Shen Xiaoxi. Unexpectedly, when Xiaoxi turned four, he began exhibiting strange symptoms and was regarded as a monster. At the critical moment, Pei Xingye appeared and saved Shen Xiaoxi! Only then did Shen Siwei discover that the mysterious man from five years ago was actually a legendary werewolf.