I pray to Truck-kun every day yet nothing. I'm starting to think it's not real.

Also, the Grim Reaper is actually based on Greek mythology as well, though some aspects may be considered Roman.

Kronos/Saturn would use his scythe to sever the soul from the body when the mortal person's time was up.

The soul would then wander to the Styx to be ferried by Charon.