Young-ho doesn't have any dreams for his life. He has been studying for three years to enter a university. He decides to send a letter to his childhood friend So-yeon. But her younger sister So-hee receives the letter instead of her sick sister. So-hee writes back to Young-ho, pretending to be So-yeon. Meanwhile, So-hee takes care of her sick sister and also runs a secondhand bookstore with her mother.
강하늘
as Young-ho
천우희
as So-hee
강소라
as Soo-jin
이설
as So-yeon
임주환
as Young-hwan
이항나
as Mother
이양희
as Father
박세현
as Student
김성균
as Teacher
고건한
as Jong-guk
남현우
as Student
김민서
as Student
