oh, sorry for this late reply!! I haven't read much in this genre yet, but some of the ones that have absolutely melted my cold dead heart:
http://www.mangago.me/read-manga/bokura_no_shokutaku/
(pure wholesomeness!! both guys are in their early twenties with their own set of problems to deal with, but oh my god did i die reading this. it's so cute i want to bite my fist)
http://www.mangago.me/read-manga/hidamari_no_orange/
(there's just the tiniest bit of teen angst, but it's understandable in the context of the story and the characters are really precious, i just want to wrap them in warm blankets and make them hot chocolate)
http://www.mangago.me/read-manga/ganbare_nakamura_kun/
(this is more of a character study. the mc is a gay teen crushing hard on his classmate and falling into all kinds of awkward situations. it's funny as hell, bubbly and sweet. it doesn't end in a romance but still this story is such a treasure. you can safely recommend it to anyone, really.)
http://www.mangago.me/read-manga/hare_no_hi_asada_nemui/
(it's bittersweet but also kind. it carries an important message. it's beautiful, i can't find words for it.)
http://www.mangago.me/read-manga/yozora_no_sumikko_de/
(this one has angst as well! the characters are working adults who reunite 11 years after high school. one of them has a kid so keep that in mind if you're not into those kind of storylines, but my god, the art is beyound stunning (in my humble opinion), it's poetic in a way and the kid is stubborn and adorable. it's my all time personal fave so obviously i'm biased, but i earnestly implore you to give it a chance.)
http://www.mangago.me/read-manga/kasegimasen_kara/
(yes an omegaverse, not it's not trashy and there's no smut. a more accurate description would be: shoujo, but make it gay, if that makes sense. all that to say, it's cute and the characters act their age. would definitely recommend)
I'm still exploring this genre so my repertoire is quite lacking. Hopefully next time i'll come with more recommendations. Until then, happy reading! (sorry for the long reply (=・ω・=)

Shuu is such a tsunder omg, what a lovely way to start the year of our lord 2021. There's a reason why I keep coming back to this genre. Idk, it's too wholesome! too sweet!! and just the whole thing felt like a warm hug, what a kind story. I hope to support the author asap, they're incredible. I would give up a kidney for a sequel i swear.