Level 1 Demon Lord and One Room Hero

The hero Max and his party slay the Demon Lord. Ten years later, the Demon Lord resurrects, but now looks like an androgynous young boy. Eager for a rematch, the Demon Lord tracks Max down, only to find that after being rejected by society, he has become an unemployed slacker who lives in a one-room apartment. The Demon Lord decides to move in with him and try to get him back into shape so that they can have their rematch, much to the frustration of the Demon Lord's secretary, Zenia.

Max (マックス, Makkusu) Voiced by: Yuichi Nakamura (Japanese); Joe Daniels (English) The legendary hero that struck the final blow against the Demon Lord ten years prior, Max grew intoxicated from fame and fell from grace. He retains most of his physical strength and mental acumen despite his slovenly appearance, although he has also become jaded over the paths his friends and humanity in general have taken. Demon Lord (魔王, Maō) Voiced by: Naomi Ōzora (Japanese); Brittney Karbowski (English) The very Demon Lord that threatened the world. After reincarnating, he personally seeks out the man that defeated him. Once he discovers the state Max is in, he vows to train Max back to the status of a hero for their inevitable rematch. Zenia (ゼニア) Voiced by: Yoko Hikasa (Japanese); Natalie Rial (English) The Demon Lord's voluptuous and fiercely loyal personal secretary. She makes up for her lack of magic ability with immense physical strength. After discovering where the Demon Lord went, she moves into the apartment next door to keep an eye on them. Fred (フレッド, Fureddo) Voiced by: Yoshitsugu Matsuoka (Japanese); Adam Gibbs (English) The cleric of Max's party who has since risen to the position of the Chief Secretary of the Kingdom's Magic Bureau. A former conman despite his strong magic abilities, Fred is easily angered and also not above using emotional manipulation and blackmail for his own personal gain. Leo (レオ, Reo) Voiced by: Hiro Shimono (Japanese); Michael Wronski (English) A physically powerful fighter and one of Max's former party members, he had allegedly defected from the Kingdom sometime after the Demon Lord's defeat to set up his own "republic", leading it to a measure of prosperity but earning the ire of his former allegiance - and his former partner - in the process. Yuria (ユリア) Voiced by: Ami Koshimizu (Japanese); Alyssa Marek (English) The wizard of Max's party who hid her genuine concern for the party's wellbeing out of pride and a personal sense of competitiveness. She retired and also disappeared from the public eye after the Demon Lord's defeat.

Written and illustrated by toufu, Level 1 Demon Lord and One Room Hero was serialized on Houbunsha's Comic Fuz website from March 29, 2019, to June 4, 2024. The series was collected into 11 tankōbon volumes released from March 2020 to July 2024. In February 2021, Seven Seas Entertainment announced that it had licensed the series for English publication in print and digital formats.

An anime television series adaptation was announced on March 29, 2022. The series was produced by Silver Link and Blade and directed by Keisuke Inoue, with scripts written by Toshiya Ono, character designs by Yoshihiro Watanabe, and music composed by R.O.N. It aired from July 3 to September 18, 2023, on AT-X and other networks. The opening theme is "One Room Adventure", performed by Madkid, and the ending theme is "Mirai=Teleport" (ミライ=テレポート), performed by Nenne. Sentai Filmworks licensed the series for streaming on Hidive. In June 2024, it was announced that the series would receive an English dub, which premiered on Hidive on August 20. Medialink licensed the series in South, Southeast Asia, and Oceania (except Australia and New Zealand) for streaming on the Ani-One Asia YouTube channel.