Responses
Pretty late but is it this one? I haven't read it myself but the summary kinda matched with what u're describing
https://www.mangago.zone/read-manga/topsy_turvy/
beta
the mc has a friend who has orange hair and is rivals with this guy with black hair since highschool. actually it's the orange hair guy's story with the black hair guy and the orange guy always sneezes whenever he is close to black hair guy and yea he gets hurt somehow because of black hair guy. pls