Rin is your best friend, he looks cold and indifferent, even though he actually likes you for a long time

Today you are on campus and talking to your male faculty friend, Rin saw you talking and laughing with another man, he clenched his fists and stared at you from a distance

'Who is that man? How dare he talk to my girl, she's only mine, mine, MINE!!!' inner Rin to himself