?

https://www.mangago.zone/read-manga/itonaga_kun_no_koi_no_ito/

They were besties, not in hs but in middle school, and then something happen and the ml bullied the mc (if you don't like this part, pls don't read the manga bcs the bully part is the key point) but later he regreted it, search for the mc and atone for his sins

https://www.mangago.zone/read-manga/shinyuu_no_dousei_shite_ni_un_to_iu_made/
https://www.mangago.zone/read-manga/mission_friend_escape/ (not really on bad terms but one of them avoided the other)
https://www.mangago.zone/read-manga/number_of_cases/
https://www.mangago.zone/read-manga/kotaete_my_drifter/
https://www.mangago.zone/read-manga/red_string_quests/
https://www.mangago.zone/read-manga/backlight_1/ (The reconciliation part is non-existent rn)