As long as the story makes sense, the main characters aren't TOO PERFECT, the plots are interesting and normally I read because even though the OTPS I ships won't be real, at least they already meet each other and know each other rather than idol x oc who probably doesn't exist.
This is just an opinion, please don't hate.^^

normally bias and oc

Must be group i like i am multifandom so no problem.
Must be couple i ship.
There can't be sad ending.
Must be interesting plot.