Manga/Manhwa/Manhua similar plot like https://www.mangago.me/recommend-manga/life_senjou_...

I cannot exactly recall any similar plots but here's some that gave me a similar feeling regarding the bittersweetness if you'd like :)
https://www.mangago.me/read-manga/kowagaranai_de_soba_ni_ite/
https://www.mangago.me/read-manga/see_you_later_mermaid/
https://www.mangago.me/read-manga/500_nen_no_itonami/
https://www.mangago.me/read-manga/bokura_ga_koi_wo_ushinau_riyuu/
https://www.mangago.me/read-manga/bokura_wa_nando_mo_koi_o_suru/
https://www.mangago.me/read-manga/kimi_no_yume_o_mite_iru/
https://www.mangago.me/read-manga/boy_meets_maria/
https://www.mangago.me/read-manga/asagao_wa_yoru_kara_saku/
https://www.mangago.me/read-manga/toumei_na_ai_no_utsuwa/

Thank you so muuuch