The Devil Is a Part-Timer!, Vol. 19

"Maou staves off the attack on Chiho's school, but it was all a diversion to draw him away from the Devil's Castle. With Ashiya kidnapped by Gabriel and Emilia still missing, the Devil King and Suzuno prepare to return to Ente Isla on an undercover rescue mission. That is, assuming Maou can find someone to cover his shifts at MgRonald first"--Publisher's description.