Sleepy Princess in the Demon Castle manga volume 7 features story and art by Kagiji Kumanomata.

Princess Syalis manages to mess up Christmas and Valentine’s Day…again. Then, when Syalis and her demon captors pay a visit to her kingdom of Goodereste, a demon stands in for the princess…and winds up needing to be kidnapped herself! A common enemy forces Syalis and her archnemesis Poseidon to team up. And Syalis messes up more things, including a Demon Castle hot pot party and a Demon King educational biopic. But she still manages to find some good opportunities for relaxing naps…