technically this kinda fits what you’re looking for since the mc is heavily implied but not confirmed fully yet in the ongoing story to be the ml’s old beloved flame but reborn without his past memories, they both absolutely fucking hate each and love each other at the same time, hence a slow burn.
I won’t spoil much else, but let’s just say it gets kinda complicated plot wise if you don’t pay attention and poor ml is gonna have to make one hell of a choice in the near future regarding mc and his old flame :(
https://www.mangago.zone/read-manga/the_mountain_branches_dream_of_goblins/
not a problem! also, if you want an ongoing horror story, I highly recommend this one since it’s all about a time loop in a horror game.
https://www.mangago.zone/read-manga/dreadful_night/
Sangyang: the wanderer. Mc and ml are guardian & heir and have been forced to be servant & master since childhood but there’s also weird supernatural shit and possibly? Past lives. It’s kinda like fated pairs and star crossed lovers simultaneously. And they keep hurting each other because of the bond forced upon them but idk I can’t get enough this hurts too good. Idk how they will end up together atp when they’re both tied together by fate but also doomed to be apart because of that same fate but I have hope (I am snorting copium).
https://www.mangago.zone/read-manga/sangyang_the_wanderer/

Might be a reach but does a satosugu adjacent couple exist in a manhwa, manhua or manga like a couple that yearn for each other but cant be together lowkey