Kɪᴍ Nᴀᴍᴊᴏᴏɴ is diagnosed with temporary amnesia after an accident he can't remember.
As he tries to regain memory of that night, he realises that he may not be able to trust those close to him.
Namjoon is in the hospital because of kidney failure. His friends bring him on their adventures of college and relationships through letters until he is released. He'll find that everything is not as it seems and that some things are worth sacrificing.