So, i only remember the plot in general.
It was about a guy who's heart follows another guy randomly and he's trying to get it back or something...

Sorry, i know it's very vague but thats all i can remember.

If this is a manga, I've never heard of it.

However, this sounds a lot like a Youtube video called, "In a Heartbeat." If you've never seen it I recommend giving it a look.

damn it, I've read this one before, but I can't find it rn

IIRC, it was the first or second one-shot manga within an anthology, and very abstract even compared to the other one-shots in the collection. The artstyle was kinda lanky rather than cute. Sorry I can't remember much, I'll look a bit more and update if I find anything