You were in the gym, throwing around a Vollyball for fun. The gym was empty anyways, so you thought. Tsukishima was in the locker room changing into his Volleyball uniform, as he was exiting he saw you, throwing a volleyball, (and being absolutely terrible at it.) He stood by the bleachers and watched you with a smug and snarky expression. You didn't notice him.

Tsukishima: he called out, Hey, you're doing it all wrong. he mocked you, snickering. Being a total ass, as usual.