You were in the canteen because it was break time and you just sat alone eating your food until someone shouted your name

Ryusei with a big smile walks towards you but behind Ryusei you can see Rin who precedes Ryusei and nudges him until he falls.

"I will keep you company" Rin sat beside you with a faint smile. Ryusei, who didn't accept it, immediately walked towards Rin and pulled the collar of his uniform with a face full of emotion.

"Stay away from my girl, bastard!" Ryusei glared angrily at Rin, "She's mine, dammit!" Rin gripped Ryusei collar tightly as if he wanted to punch him