This was a great find! I was looking for moths on a signboard not far from my home when I saw this wasp nest beetle (mumon-oo-hana-nomi) in the grass. I thought it was an oil beetle (see here) at first and then I realized that it was something I’d not seen before. The larvae of these beetles are parasites of wasps – living inside the bodies of the wasp grubs at first and then consuming the grubs from the outside. The adults lay hundreds of eggs on flowers so that wasps pick them up (accidentally) and transport them back to their nests. The several species of wasp that this beetle parasitizes are shown on the Japanese Forestry and Forest Products Research Institute website (here).
Wasp Nest Beetle = mumon-oo-hana-nomi
Location: In vegetation under lighted signboard near Genkai Royal Hotel (Google map)