, also known as Regarding Reincarnated to Slime and by the contraction , is a Japanese fantasy light novel series written by Fuse, and illustrated by Mitz Vah. The story follows Satoru Mikami, a salaryman who is murdered and then reincarnated in a sword and sorcery world as the titular slime, who goes on to gather allies to build its own nation of monsters.
It was serialized online from 2013 to 2016 on the user-generated novel publishing website Shà Âsetsuka ni Narà Â. It was later acquired by Micro Magazine, who published the story as a series of light novels from 2014 to 2025 for twenty-three volumes. The light novels have been licensed in North America by Yen Press, which published the first volume in December 2017. It has received a manga adaptation published by Kodansha along with five manga spin-offs published, by Micro Magazine and Kodansha, respectively. It has received an anime television series adaptation, produced by Eight Bit, which aired from October 2018 to March 2019. A second season of the anime series aired from January to September 2021, and an anime adaptation of the second spin-off manga aired from April to June 2021. An was released in November 2022. A three-episode original net animation spin-off, titled Visions of Coleus was released in November 2023. A third season aired from April to September 2024. A fourth season is scheduled to be released in April 2026. A was released in February 2026.
Satoru Mikami is an ordinary 37-year-old corporate worker living in Tokyo. He is almost content with his monotonous life, despite the fact that he does not have a girlfriend. During a casual encounter with his colleague, an assailant tries to stab his friend, and Satoru pushes his friend out of the way and gets stabbed instead. While succumbing to his injuries, a mysterious voice echoes in his mind and asks a series of questions. In response to Satoru's answers, the voice grants him various gifts and powers to use in his next life.
After regaining consciousness, Satoru discovers that he has been reincarnated as a Slime in an unfamiliar world. At the same time, he also acquires newfound skills, particularly the ability called "Predator," which allows them to devour anything and mimic its appearance and skills. He stumbles upon Veldora, a powerful 'Storm Dragon', who has been sealed for the last 300 years for reducing a town to ashes. Feeling sorry for him, Satoru befriends the dragon, promising to help him in destroying the seal. He decides to exchange names, Veldora bestows upon them the name Rimuru, and he receives the surname Tempest in return. Rimuru then consumes the dragon together with his prison in order to analyze the spell and eventually free Veldora. During their journey, he gains a human form after devouring a deceased human named Shizue Izawa.
The disappearance of Veldora's aura creates a power vacuum, which eventually makes Rimuru the leader of all beings inhabiting the Great Forest of Jura, who accept them as a ruler and together, they establish the nation of Tempest. With Rimuru's strength, wisdom, and idealistic vision, the new nation quickly grows in strength and influence. Soon Rimuru and their subjects draw the attention of nearby foreign powers, from monarchs and legendary heroes to demon lords, some seeking to become their allies, others intending to take advantage of or destroy them completely.
Fuse originally serialized the series as a web novel on the user-generated content site Shà Âsetsuka ni Narà  between February 20, 2013, and January 1, 2016. The series was acquired for print publication by Micro Magazine, which published the first light novel, with illustrations by Mitz Vah, under their GC Novels in May 2014. On April 15, 2017, English publisher Yen Press announced during their panel at Sakura-Con that they had licensed the series for release in North America.
A spin-off web novel series set between the ninth and tenth volumes of the light novel, titled Toaru Kyà «ka no Sugoshi-kata (How to Spend a Certain Holiday), began serialization on Shà Âsetsuka ni Narà  on February 20, 2023.
Taiki Kawakami launched a manga adaptation in Kodansha's shà Ânen manga magazine Monthly Shà Ânen Sirius on March 26, 2015. Kodansha USA announced their license to the manga during their panel at New York Comic Con on October 6, 2016.
A spin-off manga, titled , with art by Shà  Okagiri, was serialized in Micro Magazine's Comic Ride web magazine between July 28, 2016, and March 1, 2021. The series was later cancelled due to the poor health of the artist.
A second spin-off manga, titled , with art by Shiba, has been serialized in Kodansha's shà Ânen manga magazine Monthly Shà Ânen Sirius since March 2018, compiled into seven volumes as of January 2024, and licensed in English by Kodansha USA.
A third spin-off manga, titled and illustrated by Shizuku Akechi began serialization in Kodansha's Niconico-based Suiyà Âbi no Sirius manga web platform on September 26, 2018, and has been compiled into two volumes as of March 27, 2020. On June 3, 2020, Kodansha USA announced that it has licensed That Time I Got Reincarnated (Again!) as a Workaholic Slime.
A fourth spin-off manga, titled , with art by Tae Tono began serialization in Suiyà Âbi no Sirius on March 14, 2019. On March 18, 2020, Kodansha USA announced their license to the manga for a print release under the title That Time I Got Reincarnated as a Slime: Trinity in Tempest.
A fifth spin-off, a yonkoma titled , with art by Chacha, began serialization in Monthly Shà Ânen Sirius on February 26, 2019. This story differs from the main one after Rimuru's encounter with Shizu, when they learn how to mimic a human body. However, the body they create is that of a three-year-old.
A sixth spin-off manga centered around Demon Lord Clayman, titled (That Time I Got Reincarnated as a Slime: Clayman's Revenge), with art by Wataru Kajika began serialization in Monthly Shà Ânen Sirius on April 26, 2022.
A seventh spin-off manga, titled That Time I Got Reincarnated as a Slime: Gourmet Legend: Peko and Rimuru's Cooking Notebook, with art by Chika Nakatani will begin serialization in Monthly Shà Ânen Sirius on April 26, 2023.
A manga adaptation of the Toaru Kyà «ka no Sigoshi-kata web novel illustrated by Yuzo Takada began serialization in Monthly Shà Ânen Sirius on July 26, 2023. The manga is set to end serialization on May 26, 2025.
An anime television series adaptation produced by Eight Bit and directed by Yasuhito Kikuchi, was broadcast from October 2, 2018, to March 19, 2019, on Tokyo MX and other networks. A second season was announced to be a split-season anime; the first half aired from January 12 to March 30, 2021, and the second half aired from July 6 to September 21, 2021. A third season aired from April 5 to September 27, 2024, on the Friday Anime Night programming block on Nippon TV and its affiliates, as well as BS11. The fourth season is set to premiere 5 cours, with the first 2 cours premiering on April 3, 2026.
The first anime film, titled That Time I Got Reincarnated as a Slime: The Movie â Scarlet Bond, premiered in Japan on November 25, 2022. The second anime film, entitled Tears of the Azure Sea, premiered on February 27, 2026.
A spin-off anime series based on the Slime Diaries: That Time I Got Reincarnated as a Slime manga aired from April 6 to June 22, 2021.
At the AnimeJapan 2021 special stage for the franchise, a free-to-play role-playing game app, titled Tensei Shitara Slime Datta Ken: Maà  to Ryà « no Kenkoku-tan (That Time I Got Reincarnated as a Slime: The Saga of How the Demon Lord and Dragon Founded a Nation), was announced. It is developed by Bandai Namco Entertainment and was released in 2021. The game was released in English under the title That Time I Got Reincarnated as a Slime: ISEKAI Memories.
In August 2024 another game, That Time I Got Reincarnated as a Slime ISEKAI CHRONICLES, was released.
The mobile game The Seven Deadly Sins: Grand Cross had a crossover event where some of the characters of the series could be obtained for a limited time. A similar event occurred in the Japanese version of the mobile game '.
The light novel series had over 4.5 million volumes in print by October 2018. It was the fifth best-selling title of 2018 with 539,277 light novel sales, and its manga adaptation was the ninth best-selling title of 2018 with 3,460,066 copies. It also became the first manga series based on a light novel with at least 20 million total copies in print. By March 2021, it had over 24 million copies in circulation. In May 2021 it reached 25 million. In January 2022, it had over 30 million copies in circulation. In February 2023, it had 40 million copies in circulation, with 35 million copies in Japan and 5 million copies overseas.
The light novel ranked eighth in 2017 in Takarajimasha's annual light novel guide book Kono Light Novel ga Sugoi!, in the category; it ranked sixth in 2018; and fifth in 2019.
In 2017, the manga adaptation was ranked fifth at the third Next Manga Awards in the print category. The manga adaptation (along with its light novels) also won the 2018 BookWalker Award. It was nominated for the 45th Kodansha Manga Award in the category in 2021; it won the 46th edition in the same category in 2022.