Rimuru's Lab Hits a Wall
According to the Episode 85 preview on Japanese anime news site Animate Times, Rimuru is finally tackling the yorishiro (spiritual vessels) that Diablo has been asking for. The problem? There are way too many to make, and the research lab doesn't have the hands to keep up.
That staffing crunch has been a running thread this season. Tempest keeps expanding its ambitions, but the infrastructure can't always match the pace. Episode 85 puts that tension front and center, with Rimuru stuck between Diablo's expectations and the reality of limited resources.
The bigger tease comes at the end of the synopsis: "a certain Demon Lord" pays Rimuru a visit. The source doesn't name which one, but Season 4 has been juggling several Demon Lord storylines at once. Milim, Luminous, and Leon have all had plates spinning in the background, so the visitor could advance any of them.
Episode 85 Staff
The episode, titled "Atarashii Nakama-tachi" (New Companions), lists Akiko Waba on script duties. Storyboards are shared among three artists: Ryō Ogawa, Erika Nakajima, and Mizuki Nagara. Hitomi Ezoe handles episode direction, with Masayori Komine, Hideki Yamazaki, and MC Serika Yamada serving as chief animation directors.
A three-person storyboard team and three chief animation directors suggest a visually dense episode.
Where Season 4 Stands
That Time I Got Reincarnated as a Slime Season 4, produced at studio 8bit and directed by Naokatsu Tsuda, has been airing Fridays on Nippon TV and BS11 since April 3, 2026. The season is structured as five split cours, with the first two running back-to-back. The second cour kicks off July 3, placing Episode 85 right at the transition point.
The overarching story this season follows Rimuru's Jura Tempest Federation as it works toward peaceful coexistence between humans and monsters. Standing in the way: former Hero Granbell Rozzo (Daisuke Ono) and his granddaughter Mariabel (Inori Minase), who view Rimuru's rising power as a threat to humanity. Meanwhile, Demon Lord Leon is making moves of his own in El Dorado, and a dormant Hero is on the verge of awakening.
The cast remains stacked. Miho Okasaki leads as Rimuru, with Takahiro Sakurai as Diablo, Rina Hidaka as Milim, Yoshitsugu Matsuoka as Masayuki, and Natsuki Hanae as Yuuki among the key players this arc.
Looking Ahead
Episode 85 airs this Friday on Nippon TV and BS11 in Japan. Crunchyroll streams the series simultaneously across North America, Europe, Central and South America, Africa, Oceania, the Middle East, and Southeast Asia.
With the second cour beginning July 3, the season is far from winding down. The five-cour structure means Season 4 will continue well into 2027. The production team also confirmed with Episode 84's announcement that the series will have a presence at Anime Expo 2026, North America's largest anime convention, running July 3-6 in Los Angeles.
The source manga by Taiki Kawakami, based on Fuse's original light novels, is published by Kodansha in Monthly Shonen Sirius. English-language readers can follow the manga through Kodansha USA, and the light novels are available from Yen Press.
(C) Taiki Kawakami, Fuse, Kodansha / TenSura Production Committee