College student Lin Chen witnesses his classmate Sheng Nanzhi being abducted by villains. Stepping forward to save her, he and the other person are drugged and turned back into children. While temporarily staying at the Sheng household, with his extraordinary courage and knowledge, he repeatedly fends off unwarranted entanglements and exposes false scams for Sheng Nanzhi. Later, with the help of the older generation, the two recover their true forms, join hands to root out the mastermind behind the scenes, and defeat the family's power-grabbing conspiracy. Having gone through twists and turns, Lin Chen always stays true to his original intention of protecting her, and the two also grow from classmates into mutual romance, reaping a warm ending.