I saw somewhere I don't remember where but someone said that Asahi's uniform resembles that of the girl's uniform and I'm now convinced that he really likes to wear more "feminine"clothes
He finds them cute and comfortable
But remember clothes are for everyone and clothes do not have a gender so clothes are not set for one specific gender they're for EVERYONE

YOU ARE READING
Haikyuu Headcanons
FanfictionHeadcanons that I believe have happened to the characters off screen that may or may not be factual