Himitsu no Ai-chan, Naisho no Jikan Recommendations
Both girls have their school rivals catch them working at a cosplay cafe and feel vulnerable about their secret being exposed. The relationship progresses a bit differently in each case, but the general level of hysteria around keeping the secret under wraps is very similar.
both mangas involves a high school girl working as a maid in a cosplay shop and a guy whom she is enemies/rivals with who "falls in love with her<3" . both also involve a relative (uncle) who is the owner of that shop.
-Both are about girls rivalled with the school prince
-Both girls are discovered working at a maid/cosplay cafe by school prince
-Both go on dates (disguised as a cute girl) with school prince
Both are really cute, funny stories :)