Def the return of devil to school
Not sure *exactly* what you mean but these were my thoughts:
https://www.mangago.zone/read-manga/special_civil_servant/ - has art/scenes reminiscent of yaoi/bl, author also makes some hella female fanservice fanart
https://www.mangago.zone/read-manga/yabun_ni_kyuuketsu_shitsureishimasu/ - I mean... self explanatory. Author swears up and down it's not bl.
https://www.mangago.zone/read-manga/phantom_busters/ - Previous bl doujinshi author. Haven't gotten to reading it yet but read through the comments that there are gay undertones.
i’ve been wanting to try phantom busters! is it good?
any manga or manhwa (shounen, action, fantasy. you name it) that screams homiesexual