Four I can personally really recommend are:
We're Not So Different, You and I (SH)
The Reincarnated Vampire Just Wants To Enjoy Her New Life (SH)
A Monster Who Levels Up (not sure where you can find it, but not on SH nor RR)
Vigor Mortis (RR, there's technically one chapter left there till the end but good luck reading almost 200 chapters in less than a week)
I will say it now though, depending on interpretation those might not have the kind of closure you're looking for. If by closure you mean that there's nothing more to be told, then they are not that. All four end when a certain turning point in a story is passed, and what follows is left up to the readers imagination, but it's certainly not unfinished. It's like the hero goes on a journey, finally kills the demon lord, then goes back as a victor and the story ends, but he's got a long life ahead of him. That kind of ending.
Edit: Recalled another one, called An Unwilling Monster, and it's both on SH and RR.