obsessive? obsessed.

baseball!!!
MC is super disheartened when he can’t beat ML during any of his games so he loses his motivation to improve and drops into a lower league. ML winds up hunting him down to convince him to try hard in baseball again bcuz he’s (gasp) an obsessive fan who constantly re-watched MCs games (which was why MC could never beat him) and collected all his merch & stuff.
ML is super obsessive

basically MC transmigrates into a BL novel as her favorite characters (ML, who dies) villainess older sister (who also dies, big shocker). she decides to Change Her Fate and befriends ML, trying to teach him to be a functioning member of society. but, it seems to have had the wrong effect!
ML seems like a soft yan
—also has a novel!

haven’t read this one yet but it’s in the title lmao
ML is an obsessive stalker but claims he’s just doing it to protect the FL (whatever helps u sleep at night man)

personally not that into this one but I know for sure the son is a platonic yan

haven’t finished this one yet but the plot is quite interesting
ML starts showing some obsessive/possessive behavior later on in the series when MC gets cold feet :)