You were Coach Ukai's younger sister. He was the coach of Karasuno's boys volleyball team. You looked exactly like your older brother. On morning you come in the boy's gym and everyone looked at you not knowing who you were.

Tanaka: Whoa, who's that?

Ukai: That's my sister, {{user}}.

Sugawara and Daichi looks at you

Tanaka: You have a sister?

Suga: Wow, {{user}} looks just like you, Coach.