Laplace Comes Knocking in Eldorado
The synopsis, published by Japanese anime news site Animate Times alongside the new stills, splits Episode 87 between two fronts. In Tempest, Rimuru's monster nation has welcomed new companions and is beginning to operate as a nation of laws. Far away in the golden city of Eldorado, Laplace and his associates have disguised themselves as "merchants from the East" and made contact with Demon Lord Leon.
That Eldorado thread is the one to watch. Season 4's official story summary teases that Leon has started moving toward some unstated objective, and that a hero is about to awaken while the cast's competing agendas collide. The episode title, Fuon na Kehai, roughly translates to "Ominous Signs," which just about sums up the mood.
The preview also connects directly to the last two weeks of the show. The "new companions" line calls back to Episode 85, "New Companions," and the story picks up right after Episode 86, "The Black Numbers."
The Rosso Conspiracy Hanging Over Season 4
Season 4 opened with Tempest hosting its Founding Festival and signing diplomatic ties with other nations, all in service of what the English release calls the "Monster-and-Man Cooperative Alliance": a world where humans and monsters live side by side. Standing against that project are Granbell Rosso, a former hero who leads the Five Elders of the Siltrosso Kingdom, and his granddaughter Mariabell. The two believe humanity should be protected through control, and the season synopsis promises a direct collision between the Rosso family and Rimuru.
On the cast side, Miho Okasaki returns as Rimuru, Daisuke Ono voices Granbell, and Inori Minase plays Mariabell. Natsuki Hanae (Tanjiro Kamado in Demon Slayer) voices Yuuki. Returning studio Eight Bit is animating the season as a planned five-cour run, with the first two cours airing back to back since the April 3, 2026 premiere.
For Episode 87 itself, the credits list 漆原虹平 (likely Kōhei Urushibara) on script, Kaori on storyboards, and 筑紫大介 on episode direction, with a four-person team sharing chief animation director duties.
Looking Ahead
Episode 87 is next up in the weekly broadcast on Nippon TV and BS11; the Animate Times report doesn't list its exact air date. Internationally, Crunchyroll confirmed in February that it streams Season 4 as it airs in Japan. No dates have been announced yet for the season's remaining three cours.
For readers who want the source material, Taiki Kawakami's manga adaptation is published in English by Kodansha, and Fuse's original light novels are available from Yen Press.