How Not to Summon a Demon Lord

How Not to Summon a Demon Lord, also known as The King of Darkness Another World Story: Slave Magic (異世界魔王と召喚少女の奴隷魔術) is a Japanese light novel series written by Yukiya Murasaki and illustrated by Takahiro Tsurusaki. The light novels are published in English by J-Novel Club. A manga adaptation by Naoto Fukuda has been running since 2015, and is licensed by Seven Seas Entertainment. An anime television series adaptation by Ajia-do Animation Works aired from July 5 to September 20, 2018. A second season by Tezuka Productions and Okuruto Noboru aired from April 9 to June 11, 2021.

Plot
Takuma Sakamoto is a hikikomori gamer who is mysteriously transported to the virtual world of his favourite MMORPG, Cross Reverie, with the appearance of his own character in the game, the Demon Lord Diablo. The two young girls who summoned him, the pantherian Rem and the elf Shera, attempt to use a spell to make Takuma their servant, but due to his magic ring with the ability "Magic Reflection", the spell rebounds, and both end up with magic collars stuck on their necks, thus becoming his servants instead. With a serious case of social anxiety, Takuma decides to act like his character while interacting with others, and makes use of his high stats and vast knowledge of Cross Reverie's lore to survive in his new environment, traveling along with Rem and Shera to look for a way to remove their slave collars, while helping them with their own personal issues that led them to summon him in the first place.

Characters

 * Takuma Sakamoto (坂本 拓真) / Diablo (ディアヴロ)
 * Takuma was a Cross Reverie player who controlled the character @Diablo-13, known as the true Demon Lord. He always defeated players with better equipment and overwhelming skills, always holding back for being too strong. But one day he was invoked into another world, appearing in the body of his character, Diablo, finding two girls, a Pantherian and an elf, who claimed to have summoned him and that he should be a slave to one of them, but due to his ring's ability, the magic has rebound back against them, becoming his slaves. Takuma has poor social skills, resulting in him speaking as his character to communicate; it comes off idiotic (to readers) since he doesn't grow out of this, despite the fact it causes more problems than necessary.
 * Takuma was a Cross Reverie player who controlled the character @Diablo-13, known as the true Demon Lord. He always defeated players with better equipment and overwhelming skills, always holding back for being too strong. But one day he was invoked into another world, appearing in the body of his character, Diablo, finding two girls, a Pantherian and an elf, who claimed to have summoned him and that he should be a slave to one of them, but due to his ring's ability, the magic has rebound back against them, becoming his slaves. Takuma has poor social skills, resulting in him speaking as his character to communicate; it comes off idiotic (to readers) since he doesn't grow out of this, despite the fact it causes more problems than necessary.


 * Shera L. Greenwood (シェラ・L・グリーンウッド)
 * Shera L. Greenwood is an elf who is one of the two Summoners who summoned Diablo. Unfortunately, she is also a bit of a ditz; adding to the problems Diablo has to fix. It's later revealed that she is the princess of the elven kingdom of Greenwood. The reason she summoned him was to have the strength to live free.
 * Shera L. Greenwood is an elf who is one of the two Summoners who summoned Diablo. Unfortunately, she is also a bit of a ditz; adding to the problems Diablo has to fix. It's later revealed that she is the princess of the elven kingdom of Greenwood. The reason she summoned him was to have the strength to live free.


 * Rem Galleu (レム・ガレウ)
 * Rem Galleu is a pantherian who became a summoner and had no choice but to become an adventurer and continue to demonstrate its strength, her aim being to exterminate the Demon King Krebskulm that was bound to her soul. Rem typically has to deal with reeling in Sheera.
 * Rem Galleu is a pantherian who became a summoner and had no choice but to become an adventurer and continue to demonstrate its strength, her aim being to exterminate the Demon King Krebskulm that was bound to her soul. Rem typically has to deal with reeling in Sheera.


 * Alicia Crystella (アリシア・クリステラ)
 * Alicia Crystella is an Imperial Knight. She was born as a daughter of a duke house. She is a demon lord worshiper, whose mind is seriously damaged after seeing the depravity of mankind. She later betrays Diabio's group to destroy humanity by reviving Klem's true form, but fails and then reformed after helping Edelgard.
 * Alicia Crystella is an Imperial Knight. She was born as a daughter of a duke house. She is a demon lord worshiper, whose mind is seriously damaged after seeing the depravity of mankind. She later betrays Diabio's group to destroy humanity by reviving Klem's true form, but fails and then reformed after helping Edelgard.


 * Sylvie (シルヴィ)
 * Sylvie is the Grassrunner Guildmaster of the Adventurer's Guild in Faltra City.
 * Sylvie is the Grassrunner Guildmaster of the Adventurer's Guild in Faltra City.


 * Edelgard (エデルガルト)
 * Edelgard is a Fallen (Demonic Being). She is shown riding a dragon-like creature, but as she enters into combat she descends from him and fights swiftly with her glaive, this is because her demonic beast was paralyzed out of fear. She commanded the army that attacked the city of Faltra and was the superior of Gregore, but was defeated with the rest of the demonic beings by the supreme magic of Diablo. She later moves to Faltra to serve Klem.
 * Edelgard is a Fallen (Demonic Being). She is shown riding a dragon-like creature, but as she enters into combat she descends from him and fights swiftly with her glaive, this is because her demonic beast was paralyzed out of fear. She commanded the army that attacked the city of Faltra and was the superior of Gregore, but was defeated with the rest of the demonic beings by the supreme magic of Diablo. She later moves to Faltra to serve Klem.


 * Celestine Baudelaire (セレスティーヌ・ボードレール)
 * Celestine Baudelaire is the head of the Mage Association in the city of Faltra. She is thus responsible of the magical barrier around the city. Before Diablo's summoning, she was the only one in confidence of Rem's secret and she keeps a close eye on her.
 * Celestine Baudelaire is the head of the Mage Association in the city of Faltra. She is thus responsible of the magical barrier around the city. Before Diablo's summoning, she was the only one in confidence of Rem's secret and she keeps a close eye on her.


 * Klem (クルム)
 * Krebskulm is the ruler of the Fallen (Demonic Beings) who suffers from amnesia. She has a fondness for biscuits. She later turns into her true form after Rem was attacked, being restored to her former self when Rem is revived.
 * Krebskulm is the ruler of the Fallen (Demonic Beings) who suffers from amnesia. She has a fondness for biscuits. She later turns into her true form after Rem was attacked, being restored to her former self when Rem is revived.


 * Mei (メイ)
 * Mei is a catgirl maid and the manager of the "Peace of the Mind" inn where the protagonists reside.
 * Mei is a catgirl maid and the manager of the "Peace of the Mind" inn where the protagonists reside.


 * Emile Bichelberger (エミール・ビュシェルベルジェール)
 * Emile is a warrior responsible of evaluating the level of warriors in the Adventurer's Guild in Faltra. He is self-proclaimed “ally to all women”.
 * Emile is a warrior responsible of evaluating the level of warriors in the Adventurer's Guild in Faltra. He is self-proclaimed “ally to all women”.


 * Keera L. Greenwood (キイラ・L・グリーンウッド)
 * The perverted brother of Shera L. Greenwood. He wishes to make Shera into his wife to produce a pure-blooded child.
 * The perverted brother of Shera L. Greenwood. He wishes to make Shera into his wife to produce a pure-blooded child.


 * Chester Ray Galford (チェスター・レイ・ガルフォード)
 * The governor of the city of Faltra and a veteran of the fallen-human war which took place 30 years before the story occurs.
 * The governor of the city of Faltra and a veteran of the fallen-human war which took place 30 years before the story occurs.


 * Medios (メディオス)
 * A slave trader who happens to be an acquaintance of Celestine Baudelaire with whom she shared the same magical instructor.
 * A slave trader who happens to be an acquaintance of Celestine Baudelaire with whom she shared the same magical instructor.


 * Saddler (サドラー)
 * Saddler is a Paladin with a God complex and sadistic tendencies, especially toward demihumans.
 * Saddler is a Paladin with a God complex and sadistic tendencies, especially toward demihumans.


 * Lumachina Weselia (ルマキーナ・ウエスエリア)
 * A High Priestess who fled from the church who ordered her death, she is rescued by Diablo and since then views him as a god, despite his attempts to deny it. She is later escorted by Diablo and his party to Zircon Tower City.
 * A High Priestess who fled from the church who ordered her death, she is rescued by Diablo and since then views him as a god, despite his attempts to deny it. She is later escorted by Diablo and his party to Zircon Tower City.


 * Rose (ロゼ)
 * A magic automaton maid who was a originally prototype AI powered NPC that Takuma claimed and assigned to watch over the dungeon created by him. In his shut in days Takuma usually would talk about his feelings to her and due to her AI functions was able to respond as she saw fit. She is materialized in the living world of Cross Reverie along the dungeon and later reunites with Diablo, becoming his most loyal servant.
 * A magic automaton maid who was a originally prototype AI powered NPC that Takuma claimed and assigned to watch over the dungeon created by him. In his shut in days Takuma usually would talk about his feelings to her and due to her AI functions was able to respond as she saw fit. She is materialized in the living world of Cross Reverie along the dungeon and later reunites with Diablo, becoming his most loyal servant.


 * Horn (ホルン)
 * A Grasswalker demihuman who became a part timer for Diablo's party, but took temporary leave to study magic.
 * A Grasswalker demihuman who became a part timer for Diablo's party, but took temporary leave to study magic.


 * Fanis Laminitus (ファニス・ラムニテス)
 * The governor of Zircon Tower City. She is a magical marksman and later attempts to seduce Diablo.
 * The governor of Zircon Tower City. She is a magical marksman and later attempts to seduce Diablo.


 * Gewalt (ゲイバルト)
 * A paladin and summoner sent to hunt down Lumachina. He's later healed by her in an act of mercy and comes to her aid at the royal capital.
 * A paladin and summoner sent to hunt down Lumachina. He's later healed by her in an act of mercy and comes to her aid at the royal capital.


 * Tria (トリア)
 * The paladin that aided Lumachina in her escape. She was seemingly killed by one of Gewalt's summons, but was in fact imprisoned by the church and is later freed by Gewalt as a favour to Lumachina.
 * The paladin that aided Lumachina in her escape. She was seemingly killed by one of Gewalt's summons, but was in fact imprisoned by the church and is later freed by Gewalt as a favour to Lumachina.


 * Batutta (バドゥタ)
 * A veteran paladin renowned for his piety that Lumachina seeks out in Zircon.
 * A veteran paladin renowned for his piety that Lumachina seeks out in Zircon.


 * Varakness (バナクネス)
 * A general for one of the Demon Lords who attacks Zircon.
 * A general for one of the Demon Lords who attacks Zircon.


 * Vishos (ビジョス)
 * The main antagonist of Season 2, he was the corrupt Head Cardinal of the Church of Lyferia who attempted to kill Lumachina in a coup.
 * The main antagonist of Season 2, he was the corrupt Head Cardinal of the Church of Lyferia who attempted to kill Lumachina in a coup.


 * Sanro (サンロ)


 * Grun (グリューン)


 * Babylon (ババロン)
 * A self-proclaimed goddess that dresses like a Japanese high school girl and dwells within a grail found in Diablo's treasure vault. She helps Horn level up her power.
 * A self-proclaimed goddess that dresses like a Japanese high school girl and dwells within a grail found in Diablo's treasure vault. She helps Horn level up her power.

Light novels
The light novels are written by Yukiya Murasaki and illustrated by Takahiro Tsurusaki. Kodansha published the first volume under their Ranobe Bunko imprint in December 2014. J-Novel Club announced on September 28, 2017, that they had licensed the series for the North American market.

Manga
Naoto Fukuda launched a manga adaptation of the series on Kodansha's Niconico based manga service Suiyōbi no Sirius in June 2015. Seven Seas Entertainment announced their license to the manga on September 14, 2017.

Anime
An anime television series adaptation was announced in January 2018. The series was directed by Yūta Murano and written by Kazuyuki Fudeyasu, with animation by studio Ajia-do Animation Works. Character designs for the series were provided by Shizue Kaneko. Yuki Nishioka was the chief animation director. Yuki Miyamoto provided monster designs and serves as action animation director. Backgrounds were provided by Kusanagi, while Natsuko Otsuka was the color key artist. Photography for the series was directed by Teppei Satō at Asahi Production Shiraishi Studio, and Satoshi Motoyama directed the sound at Half HP Studio. The series aired from July 5 to September 20, 2018, and was broadcast on AT-X, BS Fuji, Tokyo MX, and Sun TV. The series' opening theme, "DeCIDE", was performed by the unit SUMMONERS 2+, a group composed of voice actresses Azumi Waki, Yū Serizawa, Yumi Hara, Rumi Okubo, and Emiri Katō, while the ending theme, "Saiaku na Hi demo Anata ga Suki." (最悪な日でもあなたが好き.), was performed by Serizawa and produced by HoneyWorks. The first season ran for 12 episodes.

Crunchyroll simulcast the series worldwide outside of Asia, while Funimation streamed a SimulDub of it in North America. Following Sony's acquisition of Crunchyroll, the English dub was moved to Crunchyroll. In South and Southeast Asia, Medialink licensed the series.

On April 8, 2020, it was announced that the series would receive a second season titled How Not to Summon a Demon Lord Ω, co-animated by Tezuka Productions and Okuruto Noboru, and directed by Satoshi Kuwabara, with the rest of the staff and cast members reprising their roles. The second season aired on TBS and BS-TBS from April 9 to June 11, 2021. The second season's opening theme, "EVERYBODY! EVERYBODY!", and ending theme, "YOU YOU YOU," were performed by Serizawa with collaboration by DJ KOO & MOTSU. The second season ran for 10 episodes.

Reception
The How Not to Summon a Demon Lord light novels had over 1 million copies in print as of March 2018.

Censorship
On 4 January 2023, the Australian Classification Board refused classification for How Not to Summon a Demon Lord Ω but did not provide a reason, thus banning the series from being sold, hired, advertised or imported to Australia, despite being available for streaming. On 28 June 2023, a censored version was released on Blu-ray with an MA15+ classification for "strong sexual themes and sexualised imagery."