I've Been Killing Slimes for 300 Years and Maxed Out My Level, Vol. 4 (manga)

Family, check. Trip to demon lands, check. Demon king meet and greet, che—Uh-oh. Azusa’s laid-back vacation is smashed to a million pieces when Halkara smashes into the demon king—just as the Great Slime prophesied. Can Azusa clear up the misunderstanding, or will it be off with Halkara’s head?