https://www.mangago.zone/read-manga/there_s_something_wrong_with_my_popularity/
Not high school but uni, it's cute :D
I don't remember If every single one of them is chaotic but here are some of my fav high school romances
https://www.mangago.zone/read-manga/the_story_about_you_x_me/
https://www.mangago.zone/read-manga/guang_xiang/
https://www.mangago.zone/read-manga/heesu_in_class_2/
https://www.mangago.zone/read-manga/unluckily_lucky/
https://www.mangago.zone/read-manga/too_close/
https://www.mangago.zone/read-manga/the_best_smell/
https://www.mangago.zone/read-manga/my_fiance_is_a_hottie/
https://www.mangago.zone/read-manga/kisses_x_kiss_x_kisses/
https://www.mangago.zone/read-manga/minority_1/
https://www.mangago.zone/read-manga/this_question_is_super_difficult/
https://www.mangago.zone/read-manga/serious_joke/
https://www.mangago.zone/read-manga/this_fluffy_love/
https://www.mangago.zone/read-manga/end_of_line_of_sight_30_degrees/
All of them are shounen-ai
https://www.mangago.zone/read-manga/between_the_stars/ (this is shounen-ai too but Side Stories are Mature, though here are censored)
Faded first love
https://www.mangago.zone/read-manga/19_days/
https://www.mangago.zone/read-manga/blunder_turned_wonder/
https://www.mangago.zone/read-manga/my_four_masters/
And if mangas are ok too:
https://www.mangago.zone/read-manga/prunus_girl/
https://www.mangago.zone/read-manga/sasaki_to_miyano/ + spin off https://www.mangago.zone/read-manga/hirano_to_kagiura/
https://www.mangago.zone/read-manga/yankee_no_kareshi_ga_dekiru_made/
Enjoy
Please rec a chaotic and cute high school bl manhwa pleaseee