Shoujo Manga nara Kanawanai Koi

A trio of childhood friends: a prince, a heroine, and a yankee. Suminao, a yankee, hides his unrequited love for Hiroomi, a popular prince, and tries to give up on his love, but... He can't stop blushing in situations with him!? Hiroomi is actually in love with Suminao so much so that his masculinity is on full display!

(Source: Libre, translated)