On her way to school, a young girl named So Won (which literally means "wish" or "hope" in Korean) gets sexually assaulted by a drunk older male stranger. As a result, she suffers multiple internal injuries and has to undergo a major surgery, but her emotional wounds are equally difficult to heal. Their happy family shattered, her parents Dong Hoon and Mi Hee go through feelings of pain and rage. From the trauma of that day, So Won refuses to see or talk to her father, so Dong Hoon hides beneath the costume of his daughter's favorite cartoon character and becomes a "guardian angel" at her side. Based on a true story, the infamous Nayoung Case in 2008.