There's a Demon Lord on the Floor Vol. 7 (manga)

ENTER THE CREEPY DOLL

Into this already strange establishment comes a cursed doll, plotting to absorb the power of the Demon Lord: "I sensed an evil power emanating from this establishment. I mean to make that power mine. And then...I will attain my true form!" Sit. Eat. TRANSFORM! A Demon Lord and a family restaurant come together to serve up a seventh volume of this comedy buffet!