Lewellyn's Enchanting Dinner Invitation (might have got the title a bit wrong, I never spell Lewellyn right lol), Regas, At the End of the Road, Mad Dog, Hogu Hagyeongsu (this one is fucking crazy, most toxic shit I've ever read, I feel like looking at this list this one really doesn't belong with the others but it definitely checks the box of obsessive seme, so... read at your own risk though it's really fucked up), Kanawana Koi no Musubikata (a short 6 chap one but one of my all time favorites, very gentle and respectful seme but also obsessed), My Darling Signed In, Park Hanhoo's Manager, The Nameless Flower (made me cry but has a happy ending, kind of a Rollercoaster- highs are high but lows are low)
The mangas I've listed are all very different but definitely have obsessive/possessive semes in different ways. Lmk if you're more looking for healthy and cute or toxic and fucked up
lowkey wanting to read more with that type of plot. if you have any recommendations please let me know. ╮(￣▽￣)╭