Kyungsoo keeps a notebook for each one of his friends, Writing about the memories he shares with them and about their relationships with other people, He does this to remember the good times in 20 years or more. The first Person that he meets is Baekhyun and they grow close in the first few seconds of their first class together. The last person that he meets is Jongin, the guy that claims a special part in his heart and who will always be a complete mystery to Kyungsoo.