Any recommendations where the uke/seme is in a unrequited love with someone but decides to give up and fall in love with someone else. But the unrequited love interest starts wanting them back. Idc if the unrequited love interest is the ml or not
https://www.mangago.me/read-manga/back_to_school/
https://www.mangago.me/read-manga/hate_mate/
https://www.mangago.me/read-manga/ways_of_parting/ not unrequited love per se but when the uke moves on his ex starts to want him back
https://www.mangago.me/read-manga/cosmic_boy/
So I read it a while ago and I can't remember the name. It was a completed historical manhwa. But I don't remember much.
So the ml kills the fl and the fl travels back in time to when she was a kid. She meets the ml in the market and gets into an argument. The ml dresses as a girl. The fl starts working as a servent for the ml.
I particularly loved this manhwa because it felt so real. It took a long time for the fl to forgive the ml and let go of her revenge.

Maybe with a little bit of possessive ness
4 week lovers
https://www.mangago.me/read-manga/kabukichou_bad_trip/
https://www.mangago.me/read-manga/isekai_de_toshishita_kishi_ni_sewa_wo_yakareteimasu/
https://www.mangago.me/read-manga/shitsuren_junky/