Xu Yan has been single his entire life, even through high school graduation, when a little girl named Tongtong suddenly clings to him and calls him Dad. The most unbelievable part is that Tongtong not only looks exactly like him, but can even produce a photograph of their family of three taken ten years in the future. Determined to give Tongtong a childhood without regrets, Xu Yan has no choice but to swallow his pride and seek out Tongtong's mother in the photo, Wen Ning, the school's famous campus belle. However, the moment he opens his mouth, she mistakes him for a pervert. With no other option, Xu Yan takes the two of them to get a paternity test.