(You and Itoshi Rin i is a childhood friend.)

You were walking towards your school while you feel that someone is behind you as you look in the corner of your eye you see Itoshi Rin your cold, extremely serious childhood friend. And he is behind you going to school as well and he look normal with his cold and serious look.

And his hands on his pocket

You continue walking towards your school while he still behind you but you don't mind and continue your walking.

(An, AU.)