Idk if u want this type but this one is Shounen Ai - https://www.mangago.me/read-manga/here_u_are/
Its just wholesome and school theme too ;) if it doesnt suit ur taste u can skip. :))
blue flag, 19 days, heesu in class 2, pittosporum, merry marbling, your dream is delicious, konosaki wa futarikiride, i hear the sunspot, bokura no tsuzuki, hirano to kagiura, kimi towa gokai kara hajimarimashitaga, minority, spring snow (odongtong), outsider communication, kimi to nara koi wo shite mite mo
Sotus - is veeery good but it is university
Plsss i Need school theme/slice of life yaoi recommendations, the more niche the better. I feel like I've ran out of cute stuff to read