NOIZ

https://www.mangago.me/read-manga/sea_foam/ (and almost everything by this author)
https://www.mangago.me/read-manga/december_rain/ https://www.mangago.me/read-manga/life_senjou_no_bokura/ https://www.mangago.me/read-manga/never_understand/ https://www.mangago.me/read-manga/kami_no_kodomo/ https://www.mangago.me/read-manga/boy_meets_maria/ https://www.mangago.me/read-manga/my_broken_mariko/ https://www.mangago.me/read-manga/10_years_where_i_loved_you_the_most/ https://www.mangago.me/read-manga/save_me/

Make Me Bark
Be My Dog (no idea what it's about but I've seen the cover so many times)

I have a straight one with a muzzle and I know a few with masks, but not like normal paper/fabric masks.

Oh jfc. Wrong thing I replied to.

My answer for this is Fruits Basket. Super basic, but, I read it at like 13 and it kind of grounded me during a rough patch when my mom and I were arguing a lot because of, well, fresh teenager angst.

Not that old but cheese in the trap I think that’s the name smart female lead and kinda creepy ml but they end up together

this one kinda fits! - http://www.mangago.me/read-manga/beauty_pop/

hi! try these:
http://www.mangago.me/home/mangalist/835152/
http://www.mangago.me/read-manga/say_i_love_you/
http://www.mangago.me/read-manga/gakuen_alice/
http://www.mangago.me/read-manga/sabaku_no_harem/
^It's not super old
http://www.mangago.me/read-manga/reimei_no_arcana/
http://www.mangago.me/read-manga/bloody_mary_samamiya_akaza/
http://www.mangago.me/read-manga/oresama_teacher/
http://www.mangago.me/read-manga/skip_beat/
http://www.mangago.me/read-manga/strobe_edge/
http://www.mangago.me/read-manga/akuma_to_love_song/
http://www.mangago.me/read-manga/akagami_no_shirayukihime/
http://www.mangago.me/read-manga/ouran_high_school_host_club/
http://www.mangago.me/read-manga/mahou_tsukai_no_yome/
http://www.mangago.me/read-manga/usotsuki_ouji_to_nisemono_kanojo/
http://www.mangago.me/read-manga/takane_to_hana/

Thanks for all the recommendations!