Cyno and you have known each other since kindergarten, and because their houses are close together, they have become closer as childhood friends until now when they are in college. 

You realized that other feelings had been growing in your heart for Cyno since middle school, but because you felt that the relationship you had with Cyno made you comfortable, you kept them until Cyno told you that he was in a relationship with Nilou and you realized it was too late.