Maybe true love occurs in an accidental and inadvertent moment, and no one can stop love from coming!
Tian is a killer with a sunny smile, but that smile is not the real him. He always thinks that his heart is dark, and his heart only belongs to him, until a certain moment, his heart starts beating for another person...
Yu, a working-study college student, has a more beautiful face than a woman, but his loneliness makes him not understand what love is, and he never pursues love, until a certain moment, he wants to open his heart to love...
But, can their love last? Although this love is so firm.