please recommend me some completed straight romance manga (the unpopular ones)

https://www.mangago.zone/read-manga/kiyoku_yamashiku_modokashiku/
https://www.mangago.zone/read-manga/ohayou_ibarahime/
https://www.mangago.zone/read-manga/immortal_rain/
https://www.mangago.zone/read-manga/tsuka_no_ma_no_ichika/
https://www.mangago.zone/read-manga/boku_no_gemini/
https://www.mangago.zone/read-manga/natsuaki_kun_wa_kyou_mo_kokuhaku_shitai/
https://www.mangago.zone/read-manga/primitive_boyfriend/
https://www.mangago.zone/read-manga/madame_petit/
https://www.mangago.zone/read-manga/kujira_no_kora_wa_sajou_ni_utau/
https://www.mangago.zone/read-manga/kawaii_hito_saitou_ken/
https://www.mangago.zone/read-manga/hosaka_sensei_no_ai_no_muchi/
https://www.mangago.zone/read-manga/kijima_san_to_yamada_san/
https://www.mangago.zone/read-manga/futarijime_romantic/

Have you tried any of these?

https://www.mangago.zone/read-manga/match_made_in_hell/ I know you said manga, but this one BADLY needs more love. The whole plot develops and unfolds beautifully, and the characters actually have depth and are realistically portrayed. It wasn’t dragged on too long either. One of the best, most underrated, well written stories in this platform!