How Not to Summon a Demon Lord

異世界魔王と召喚少女の奴隷魔術 (Isekai Maou to Shoukan Shoujo no Dorei Majutsu)

6.8(2)

OtakuDen

6.8(462,277)

MAL Score

Ranked #5962

Popularity #289

Action
Comedy
Ecchi
Fantasy
Romance
Harem
Isekai

Episodes: 12
Duration: 23 min per ep
Aired: Jul 5, 2018 to Sep 20, 2018
Status: Finished Airing

Synopsis

In the MMORPG Cross Reverie, the feared Demon King Diablo reigns supreme, armed with the rarest gear and an unbeatable level. Behind that intimidating avatar is Takuma Sakamoto, a socially awkward shut-in who lives for the game. Everything changes when a summoning spell pulls him into another world—one that looks a lot like Cross Reverie—and he arrives wearing Diablo’s face.

He’s met by the two summoners responsible: Rem Galeu, a small Pantherian adventurer, and Shera L. Greenwood, an elf with powerful magic. Their attempt to bind him with an Enslavement Ritual goes wrong, leaving them tied to him instead. Keeping up Diablo’s domineering persona, Takuma travels with the pair as they search for a way to break the contract, all while he tries to navigate life as the “Demon King” in a very real fantasy world.

Otaku Consensus

How Not to Summon a Demon Lord earns its popularity by treating overpowered isekai wish fulfillment as a character-comedy engine rather than a lore lecture, with Yuuta Murano’s brisk direction and Kazuyuki Fudeyasu’s 12-episode structure keeping the banter, battles, and roleplay anxiety moving. Its three-lead chemistry is the main reason critics and fans defend it, while the recurring ecchi escalation is the most consistent complaint, often cited as distracting from the sharper fantasy-comedy material.

Why You Should Watch

Watch this if you want an isekai power fantasy that understands the joke of being trapped inside an intimidating MMO persona, without committing to the grim empire-building of Overlord. It scratches a similar itch to KonoSuba in the way it punctures heroic posturing, but it is more harem-forward, more ecchi, and more interested in the gap between social anxiety and theatrical dominance. The appeal is not deep world politics; it is the rhythm of Diablo trying to sound invincible while Rem and Shera turn the party dynamic into a running pressure test. If you like magic battles, kemonomimi and elf heroine archetypes, and comedy built around awkward performance rather than pure parody, this is one of the more immediately watchable 2018 isekai entries.

Key Characters

D
Diablo(VA: Masaaki Mizunaka)
Diablo is memorable because his fearsome anti-hero presentation constantly collides with the social awkwardness underneath, making his bravado both a power fantasy and a punchline.
R
Rem Galleu(VA: Azumi Waki)
Rem anchors the party with a guarded, kuudere-leaning presence that gives the comedy a sharper edge than the usual mascot-like catgirl archetype.
S
Shera L. Greenwood(VA: Yuu Serizawa)
Shera is the series’ most overtly chaotic heroine, turning the elf-princess fantasy template into a source of sunny impulsiveness, fanservice, and party friction.

What Makes It Stand Out

1
Ajia-do’s 2018 adaptation runs a compact 12 episodes, which keeps the first season closer to a fast fantasy-comedy road show than a slow-burn worldbuilding isekai.
2
The series is built around a deliberately narrow central trio, and that focus is a major reason reviews single out the leads as more likable than the show’s stock genre setup suggests.
3
AniList’s tag profile is unusually blunt about the show’s identity: Isekai at 97%, Magic at 87%, Female Harem at 80%, Nudity at 71%, and Slavery at 67%, making its tonal priorities easy to identify before watching.
4
The adaptation pairs original character designer Takahiro Tsurusaki’s fantasy-harem look with Shizue Kaneko’s anime character designs, giving the cast a glossy, archetype-forward visual identity that fits its ecchi comedy angle.
5
Its reception pattern is distinctive: despite a modest MAL score of 6.8 and AniList score of 66/100, it sits at MAL popularity #289 with over 462,000 votes, indicating broad viewership beyond its critical ranking.

Fun Facts & Trivia

Fun fact 1: The anime aired as a Summer 2018 TV series from July 5 to September 20, 2018, finishing its first season in a single cour of 12 episodes.
Fun fact 2: Yukiya Murasaki is credited with the original story, while Takahiro Tsurusaki provided the original character designs that Shizue Kaneko adapted for animation.
Fun fact 3: Kazuyuki Fudeyasu handled series composition, a key role for a show whose reception depends heavily on balancing harem comedy, action beats, and ecchi timing.
Fun fact 4: The production credits separate prop design and creature design between Yuuichi Nakajima and Yuuki Miyamoto, reflecting how the anime treats game-like equipment and fantasy monsters as distinct visual categories.
Fun fact 5: The wider review conversation is unusually consistent: even positive writeups praise the show as fun and likable while singling out the ecchi material as the element most likely to push viewers out of the story.