ramparts of ice. it's a webcomic iirc. it starts with a quiet girl becoming more proactive in talking to her classmates (there's an anime airing rn too!) and other friend groups/classes are present in the series too like mha and assclass. it is romance/drama genre
if you like saiki, you might enjoy reading Yugami-kun doesn't have friends. it features a boy who doesn't want to have friends or get involved unnecessarily with his classmates, BUT everyone is normal unlike in saiki lmao. it's still really funny and heartwarming at times like saiki imo. my fav manga of all time
school rumble reminds me of saiki k too how the whole class is involved, but it's a romcom story
A Terrified Teacher at Ghoul School! the teacher is a protagonist and it's like a found family type + fish out of water story. the teacher gets to know all the students in his class as a new teacher at the school
the first two recs don't have as inclusive of a cast among the whole classroom like mha and saiki unfortunately, those two are unique bc I feel like it's challenging to make a good series with 15+ students
silver spoon is from the same author has full metal alchemist and is about a city boy going to a farming agricultural school and learning with classmates about the industry
there's kakegurui and classroom of the elite too, both them were fine for me in the beginning
all my recs except yuguami have anime

any good reccs where the main characters are classmates? like mha, assassination classroom, superheroes of class f, those kinds! even better if it's a webtoon :D thanks!