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 (Japanese: 異世界魔王と召喚少女の奴隷魔術, Hepburn: Isekai Maō to Shōkan Shōjo no Dorei Majutsu, transl. "The Other World Demon Lord and the Summoning Girl's Slave Magic") 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.

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.

Voiced by: Masaaki Mizunaka (Japanese); Eric Vale (English)

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.

Voiced by: Yu Serizawa (Japanese); Sarah Wiedenheft (English)

Shera L. Greenwood is an Elf who is one of the two Summoners who summoned Diablo. The reason she summoned him was to have the strength to live free. She is 15.

Voiced by: Azumi Waki (Japanese); Jad Saxton (English)

Rem Galleu is a Pantherian who became a summoner and had no choice but to become an adventurer and continue to demonstrate its strength, saying to aim to exterminate the Demon King Krebsklum. It is later revealed that the soul of Krebskulm is sealed in her body and in case she dies the soul will be released. She is 14.

Voiced by: Yumi Hara (Japanese); Sara Ragsdale (English)

Alicia Crystella is an Imperial Knight. She was born as a daughter of a duke house.

Voiced by: Rumi Okubo (Japanese); Leah Clark (English)

Sylvie is the Guildmaster of the Adventurer's Guild in Faltra City.

Voiced by: Emiri Katō (Japanese); Kristi Rothrock (English)

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 spear, 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.

Voiced by: Sayaka Senbongi (Japanese); Marissa Lenti (English)

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.

Voiced by: Atsumi Tanezaki (Japanese); Madeleine Morris (English)

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.

Voiced by: Yūka Morishima (Japanese); Kimberly Grace (English)

Mei is a maid and the manager of the “Peace of the Mind” inn where the protagonists reside.

Voiced by: Ryōtarō Okiayu (Japanese); Clifford Chapin (English)

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”.

Voiced by: Akira Ishida (Japanese); Stephen Fu (English)

The brother of Shera L. Greenwood. He wishes to make Shera into his wife to produce a pure-blooded child.

Voiced by: Akio Ōtsuka (Japanese); Brian Mathis (English)

The governor of the city of Faltra and a veteran of the fallen-human war which took place 30 years before the story occurs.

Voiced by: Sayaka Ohara (Japanese); Morgan Garrett (English)

A slave trader who happens to be a acquaintance of Celestine Baudelaire with whom she shared the same magical instructor.

Voiced by: Daisuke Namikawa (Japanese); Anthony Bowling (English)

Saddler is a Paladin with a God complex and sadistic tendencies.

Voiced by: Miku Itō (Japanese); Amber Lee Connors[ (English)

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.

Voiced by: Aoi Koga

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.

Voiced by: Fumiko Uchimura (Japanese); Juliana Pagan[ (English)

She is 12. She is a part timer for Diablo's party but took temporary leave to study magic.

Voiced by: Chinatsu Akasaki

Voiced by: Kazuyuki Okitsu[ (Japanese); Garret Storms (English)

Voiced by: Maki Kawase[ (Japanese); Kimmie Britt (English)

Voiced by: Kazuhiro Yamaji (Japanese); D. C. Douglas (English)

Voiced by: Shinnosuke Tachibana

Voiced by: Kohsuke Toriumi

The main antagonist of Season 2

Voiced by: Ayumu Murase

Voiced by: Kazutomi Yamamoto

Voiced by: Akane Fujita

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.

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.

An anime television series adaptation was announced in January 2018. The series is directed by Yūta Murano and written by Kazuyuki Fudeyasu, with animation by studio Ajia-do Animation Works. Character designs for the series are provided by Shizue Kaneko. Yuki Nishioka is the chief animation director. Yuki Miyamoto provides monster designs and serves as action animation director. Backgrounds are provided by Kusanagi, and Natsuko Otsuka is the color key artist. Photography for the series is directed by Teppei Satō at Asahi Production Shiraishi Studio, and Satoshi Motoyama is directing 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. Crunchyroll simulcast the series worldwide outside of Asia, and Funimation streamed a simuldub of it in North America. In South and Southeast Asia, Medialink licensed the series. The series' opening theme, "DeCIDE", is performed by the unit SUMMONERS 2+, a group composed of voice actresses Azumi Waki, Yū Serizawa, Yumi Hara, Rumi Okubo, and Emiri Katō, and the ending theme, "Saiaku na Hi demo Anata ga Suki." (最悪な日でもあなたが好き。, "I Like You Even on the Worst Day."), is performed by Serizawa and produced by HoneyWorks. The first season ran for 12 episodes.

On April 8, 2020, it was announced that the series will 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," are performed by Serizawa with collaboration by DJ KOO & MOTSU. The second season ran for 10 episodes.

• 1 "The Demon Lord Act"

Takuma Sakamoto, a secluded gamer, is transported into the world of his favorite game, Cross Reverie with the appearance and powers of his own character in the game, the Demon Lord Diablo, where the Pantherian Rem Galleu and the Elf Shera L. Greenwood accidentally fall into an enchantment that bound them to him as his slaves. The trio settle in an inn in Faltra City, where they meet Celestine Baudelaire, the head of the Mage Association. The slave collars around Rem and Shera's necks cannot be removed or destroyed, so Celestine promises to find out how to do so. Suspecting Rem is keeping secrets, Diablo forces her to confess in private that the Demon Lord Krebskulm was sealed inside her body ever since she was born. Celestine is the only one who knows, and they have been working on a way to extract and slay Krebskulm without killing her. Diablo vows to help her with her problem. Later, when Diablo takes a walk, the disgruntled mage Galluk attacks him with a giant, fire-breathing salamander, only to be shocked when Diablo easily slays it. He declares he is Diablo, the Demon Lord from Another World!!

• 2 "The Strongest Newcomer"

Diablo, Rem, and Shera join the Adventurer's Guild, but when they try to measure Diablo's Level, the power-measuring device malfunctions. The guildmaster, Sylvie, is intrigued, then sends them on a quest to slay a Madara Snake in the Man-Eating Woods. Once there, they are ambushed by a squad of Elves who reveal that Shera is the Princess of Greenwood and wish for her to return home, and had been told that Diablo enslaved her. Shera refuses to return because her brother had been pressuring her to marry him and bear his child. The Elves attack Diablo, who easily defeats them. Galluk, the one who told the Elves where to find them and desires revenge against Diablo, comes out of hiding and berates the Elves for their failure, then retreats after being reprimanded by Rem. Shera tells the Elves to return and tell her brother she is never coming home.^

• 3 "Fallen Assault"

Diablo and Shera are given a quest to deliver refreshments to the guards at the Bridge of Ulug. Emile Bichelberger, who thinks Shera and Rem are unwilling slaves, attacks Diablo and is quickly defeated, then the girls explain the situation to him, so he leaves. As Diablo and Shera make the delivery, the guards report a massive army of Fallen is approaching. Aware the guards will not survive without help, Diablo volunteers to defend the bridge. Back in the city, Celestine tells Rem that she fired Galluk for his actions, then states her suspicions that Diablo is actually a Fallen. Galluk bursts in and hysterically demands to hear that he wasn't fired. He suddenly stabs himself with a cursed dagger, causing his body to be possessed and transform into the Fallen Gregore. Diablo defeats the Fallen left and right, then their commander, Edelgard, appears and challenges him to a duel.

• 4 "Point-Blank War Dance"

Gregore pursues Celestine and Rem, aiming to kill Celestine to destroy the protective barrier she placed around the city. When they are cornered, Emile and several adventurers defend them. Edelgard is unable to significantly harm Diablo. When a messenger explains the situation with Gregore, Diablo fires a massive spell called White Nova that erases the Fallen army and most of the land, but to Diablo's amazement, Edelgard is only left naked and is mostly unharmed, and she acknowledges him as a Demon Lord. Diablo teleports himself and Shera back in time to save Emile from being killed. Vengeful for all the people Gregore hurt and killed, Diablo humiliates him with his magic until he begs for mercy, then kills him. After funerals are held for the people killed in Gregore's attack, Shera attempts to seduce an exhausted Diablo, only to be attacked by a jealous Rem. Sylvie delivers a message saying Shera must be returned to Greenwood within ten days or else there will be war.

• 5 "Imperial Knight"

Diablo is angered when he learns Shera's brother put a bounty on her. The group meets Chester Ray Galford, the Lord of the City, who asks them to do their best to prevent a war since Shera refuses to return to Greenwood. Chester assigns Alicia Crystella, an Imperial knight, to assist them. Diablo purchases a scythe so he can fight weaker opponents without using magic. Shera is abducted by bounty hunters, but is rescued by the group plus Emile. Alicia berates herself for not guarding Shera better, but Diablo tells her not to be so hard on herself.

• 6 "Slave Market"

Celestine directs the group to the slave trader, Medios, who was once Celestine's colleague in studying magic, for insight on how to remove Rem and Shera's collars. When they meet Medios, she detects Krebskulm's presence within Rem, but Shera thinks she is saying Rem is pregnant. Medios explains a master can remove a collar by pouring their magical energy into their slave's body. Diablo tries it with Shera, but gives up in embarrassment when the process is extremely pleasurable for her. Later, Shera's brother, Keera, arrives and apologizes for the bounty hunters, then tries to persuade Shera to return with him. She reiterates that she will not return, so he leaves, promising that she will return with him of her own free will.

• 7 "Change of Heart"

Diablo dreams of his childhood where many of his so-called friends would use him and then abandon him. While alone with Shera, he finds he can easily craft potions. Outside, Keera plays a flute that hypnotizes Shera into leaving with her brother. Depressed about being abandoned again, Diablo mopes, but Rem and Alicia eventually deduce that Shera was hypnotized and the group plots a rescue. Keera chains Shera up in his tent and interrogates her on her relationship with Diablo, not believing her when she says Diablo did not touch her. Keera unleashes a fabric-eating slime creature to destroy her clothes and prepares to rape her, but the group arrives in time, having already defeated his guards. Keera uses the flute to hypnotize Shera again and make her lie that she wants to stay with her brother, but Diablo uses his authority as the master of her collar to make her tell the truth, and she says she wants to stay with Diablo and Rem. Infuriated, Keera summons a monster called the Force Hydra.

• 8 "Hero's Charge"

Diablo manages to defeat the Force Hydra despite its regeneration by completely incinerating it. Shera asks him to spare Keera as he is still her brother and he agrees, but Chester appears and beheads Keera. Chester has his army round up the already beaten Elf troops and attempts to capture Shera, stating his plans to conquer Greenwood. Chester traps Diablo in an energy sphere and destroys Alicia's sword when she tries to defend Shera. Diablo breaks free and battles Chester, evenly matched, and narrowly manages to win. Alicia threatens to report Chester's unethical actions to the King, so he surrenders and withdraws his troops. The group heals the Elf troops with potions and comforts Shera over the loss of her brother. Later, Sylvie serves an exhausted Diablo a drink meant to restore energy, but he becomes drunk and mistakes her for a body pillow. He grabs and caresses her, much to her embarrassment.

• 9 "Holy Knight Tale"

While Alicia has an audience with the King, she runs into Saddler, an arrogant Paladin, who is going to Faltra City to investigate Diablo. Shera summons a bird called a Turkey Shot and binds it to her with a collar. Diablo teaches her how to take advantage of the Turkey Shot's ability to share what it sees with its owner to improve her aim with arrows. While Shera and Rem bathe in a river, Edelgard appears, saying she is not here to fight but to confirm Rem holds Krebskulm within her. They explain Rem's situation to Shera and Shera promises to help her. Edelgard explains a ritual to be done in three days at Starfall Tower can remove Krebskulm without harming Rem, then leaves after they agree. Three days later, Alicia returns and warns them about Saddler. Despite their attempts to avoid him, he and his followers find them. Saddler condemns Diablo's friends for consorting with a Demon Lord and injures Rem with magic. He then tries to turn Diablo to stone, but Diablo reflects the spell and Saddler is turned to stone. The group goes to Starfall Tower

• 10 "The Demon Lord's Resurrection"

Edelgard explains Diablo must pour his magical energy into Rem through her vagina to release Krebskulm. Despite his embarrassment, he does it, and what emerges is at first a towering, hideous demon, but then it transforms into a cute little girl. Krebskulm has amnesia, and when Shera feeds her biscuits, she is enamored with the taste and decides not to wipe out the mortals. Alicia protests, but Edelgard is loyal to Krebskulm and accepts it. Disappointed in Krebskulm's weaker form and refusal to kill, the Fallen Eulerex appears and attacks her, but Edelgard and Diablo drive him away. As they approach Faltra City, Edelgard leaves since Fallen are not welcome. They change Krebskulm's name to Klem to avoid a panic. An exhausted Diablo is embarrassed when Shera and Klem strip and rub against him to donate magical energy. In private, Alicia remembers how she suffered from abusive parents and superiors and wants Krebskulm to wipe out all the mortal races. Meanwhile, Sadler turns back to flesh and vows revenge.

• 11 "The Young Girl Awakens"

The group tells Celestine about Klem and she is happy that the Demon Lord is not evil. While separated from Shera and Diablo, Alicia betrays Rem and Klem to Saddler and they are arrested. Alicia's plan is to traumatize Klem until she returns to her true self. Saddler takes them to a church where he intends to torture Rem until she confesses to worshiping a Demon Lord. Diablo and Shera search for them, while a massive army of Fallen marches toward Faltra City. Klem tries to protect Rem, but when Saddler attempts to strike her, Rem shields her with her body and is impaled several times. Klem snaps, returns to her original demon form, kills Saddler, and blows up the church. As she rampages, Diablo and Shera arrive.

• 12 "Battle for Legitimacy"

Alicia joins the army of Fallen and she, Edelgard, and Eulerex celebrate the return of the true Krebskulm. While Shera treats Rem's injuries with potions, Diablo battles Krebskulm and greatly damages her, but cannot keep her down. After Emile protects the girls from debris, Rem reveals she is all right, causing Krebskulm to revert to the little girl Klem. The army of Fallen turns on Alicia for her failure, but Edelgard holds them off and tells her to escape. Sylvie attempts to kill Klem for the destruction she caused, but relents when Diablo casts the spell to bind Klem to him as a slave and make a collar appear around her neck, as a slave cannot disobey their master. Later, Alicia appears and reveals she sneaked Edelgard, heavily injured from fighting off the other Fallen, into the city and begs Klem to heal her, which she does. Klem orders Edelgard to never kill mortals again. Rem asks Alicia why she did what she did and she reveals her past suffering and desire to wipe out the mortal races. Since Klem will not kill, Alicia attempts suicide, but Diablo stops her and tells her to find a new purpose to live for, then Rem forgives her. Diablo collapses in exhaustion and is embarrassed when all five girls strip and rub against him to donate magical energy. The next day, Edelgard disguises herself as a human and mingles with the people. Alicia leaves for a new journey. Shera and Rem ask Diablo choose one of them and kiss her, but he refuses, as he is a Demon Lord and only does what he wants.

The light novels had over 1 million copies in print SO of March 2018. The anime has since been ranked the 7th most viewed of 2019 by Crunchyroll.