Young-ho does not have any type of desires for his life. He has actually been examining for 3 years to get in an university. He chooses to send out a letter to his childhood years good friend So-yeon. However her more youthful sister So-hee gets the letter rather than her sick sister. So-hee composes back to Young-ho, making believe to be So-yeon. At the same time, So-hee deals with her unwell sister and likewise runs a pre-owned book shop with her mother.