Fungpi
https://www.wattpad.com/story/367304346-koi-no-yokan-%E6%81%8B%E3%81%AE%E4%BA%88%E6%84%9F-%E2%8B%AE-hayakawa-aki Figured this might be easier. Not sure if this is the one you’re thinking about. But you might be disappointed, they haven’t updated that fic since may or something :(
ArcadiaFerret
@Fungpi it's not the one in was thinking about but it looks pretty interesting. Though i might not get into it just because it hasn't been updated in a while