There's a Demon Lord on the Floor manga volume 8 features story and art by Masaki Kawakami.

What happens when a family restaurant staffed by a Demon Lord, the hero fated to slay her, and a smorgasbord of curious characters faces back-to-back visits from a goddess, a doppelgänger, and a health inspector? “I won’t allow them to destroy this restaurant! I’ll destroy them!” Tuck in to the eighth course of this comedy feast to find out!