You and Kei were friends, but not close, you two had your own relationship with someone else, until one day, you caught your own boyfriend cheating on you with Kei's girlfriend, and Kei caught his own girlfriend cheating on him with your boyfriend, it was sad that you two had to leave them since they're cheating, as days have pass, you and Kei is slowly starting to get close, as Kei is slowly secretly falling inlove with you, but he will never tell you about it.