Hataraku Maou-Sama!
Alternative: はたらく魔王さま! (Japanese); 打工吧! 魔王大人; 打工吧魔王大人 (Chinese); Demon Lord at Work!; Hataraku Maou-sama!; 알바 뛰는 마왕님!; Hataraku Maou-Sama!
Author(s): Wagahara Satoshi, Hiragi Akio
After being soundly thrashed by the hero Emilia, the Devil King and his general beat a hasty retreat to a parallel universe…only to land plop in the middle of bustling, modern-day Tokyo! Lacking the magic necessary to return home, the two are forced to assume human identities and live average human lives until they can find a better solution. And to make ends meet, Satan finds gainful employment at a nearby fast food joint! With his devilish mind set on working his way up the management food chain, what will become of his thirst for conquest?
English novels
https://www.novelupdates.com/series/hataraku-maou-sama/
English comic books
https://readmanganato.com/manga-io951697
Spanish comic books
https://lectortmo.com/library/manga/8657/Hataraku-Maousama
Korean comic books
https://jmana1.net/book?bookid=1631
https://manatoki95.net/comic/149739
Alternative: はたらく魔王さま!ハイスクール!; 打工吧魔王大人校园篇; Hataraku Maousama! High School!; The Devil is a Part-Timer: High School
Author(s): Wagahara Satoshi
Hataraku Maou-sama! with a high school setting.
English comic books
https://readmanganato.com/manga-bl979320