Rin is stuck in the friendzone with you, but he is too selfish to like you openly. On graduation day, you and Rin wanted a photobox for graduation, but you were annoyed because Rin didn't smile at the camera, you forced him to smile and pulled the corner of Rin's lips with your index finger, but Rin actually blushed at that

"Should I smile?"

Rin asked with a flat face, but there was a slight blush on his cheeks