Leon Finally Makes His Move
Leon Cromwell has spent Season 4 circling the edges of the story from his golden land of El Dorado. Episode 89 puts him at the center. According to the advance synopsis published by Oricon News, a Japanese entertainment news outlet, Leon has been searching for Chloe Aubert, and his hunt now points him toward Lubelius. To get there, he asks Elmesia, ruler of the Sorcerer Dynasty Sarion, for her cooperation.
The catch is what's waiting on the other end. By the time Leon reaches Lubelius, the army of Granbell Rosso is already preparing to invade the holy land. The episode title frames Lubelius as a point of convergence, and the synopsis backs that up: a Demon Lord, a sorcerer dynasty, and a former Hero's forces are all closing in on the same city.
Oricon also released a batch of ten advance stills alongside the synopsis, teasing at least one character appearance the outlet itself flagged as a surprise.
Where Season 4 Stands
Season 4's throughline, per the official introduction, picks up after the Founding Festival. Rimuru's nation of Tempest has opened diplomatic relations with other countries and is working toward a world where humans and monsters live side by side. Not everyone is on board. Granbell Rosso, a former Hero, and his granddaughter Mariabell Rosso see Rimuru's rise as a threat and have been scheming against him under the banner of protecting humanity through control. Meanwhile, the introduction teases that another "Hero" is about to awaken.
The season itself is a marathon. Produced at Eight Bit, the studio behind the entire TV series, Season 4 launched on April 3, 2026, as a planned five-cour run, and its second cour has been airing since July 3, 2026, in Nippon TV's Friday Anime Night block. Episode 89's numbering counts from the very first episode in 2018, a continuous count few currently airing anime can match.
A 62-Million-Copy Franchise
The series follows Satoru Mikami, an office worker who is stabbed to death by a random attacker and wakes up in another world as a slime. Taking the name Rimuru, he sets out to build a nation where every race can live happily, stacking up skills and allies through equal parts wit and nerve.
The story began as a web novel by Fuse on Shōsetsuka ni Narō, a Japanese web fiction site, before Taiki Kawakami's manga adaptation helped push the series past 62 million copies in circulation. The anime premiered in October 2018, with Season 2 airing across two cours in 2021, Season 3 running April through September 2024, and a theatrical film released in 2022. A second theatrical film is currently playing in Japanese cinemas.
Looking Ahead
Episode 89 airs Friday, August 7, 2026, in Japan, with Crunchyroll streaming Season 4 for international viewers as it airs; earlier seasons are also available on Netflix in some regions. For readers who want to get ahead of the anime, Taiki Kawakami's manga is published in English by Kodansha, and Fuse's original light novels are available from Yen Press. With three more cours still to come after the current one, Lubelius looks like the season's first major collision point rather than its last.