Hiiro Ishibashi is attached to three television anime in 2026: as Euini in Witch Hat Atelier, as Mutsumi Hojo in the new Sgt. Frog, and as Fushigi Senno in Horror Collector. The two fall series have confirmed premiere dates and casts set before broadcast.
Hiiro Ishibashi's 2026 slate runs from an established adaptation to two fall premieres. In Witch Hat Atelier, based on Kamome Shirahama's manga, Ishibashi was cast as Euini, a character who joins the story in episode 11 after the series premiered on April 6 on Tokyo MX and other channels. Euini appears in the Second Pentagram Test Arc alongside Ryusei Nakao's Sasaran, and the two roles were announced together on June 1. Ayumu Watanabe directs at BUG FILMS, and Crunchyroll streams the series as it airs with an English dub.
Two September announcements put Ishibashi in the supporting cast of fall series whose production details were already fixed. In Sgt. Frog, the new Keroro Gunsō television anime, he voices Mutsumi Hojo, one of five cast additions revealed with a second main trailer on September 14. The additions fill out the Hinata household and its neighbors, and the anime premieres October 3 on TV Tokyo with an opening theme by ano and an ending theme by PURPLE BUBBLE.
Horror Collector is the third title and the farthest along in confirmed specifics. The adaptation debuts on NHK on October 10 with a 12-episode run, and Ishibashi voices Fushigi Senno. Jun Fukuyama, Saori Hayami, and Nobuhiko Okamoto round out the announced cast, with Yuki Inaba directing at Studio Palette and handling series composition and Kaori Yoshikawa on character design. Shikao Suga performs the opening theme, "Kageboshi."
Across the three, the pattern is fixed casting rather than late additions: each announcement arrived with premiere dates, broadcasters, or episode counts already attached. Witch Hat Atelier had begun airing before Ishibashi's role was confirmed; the two fall series named him before their October starts.
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The Horror Collector anime will debut on NHK on October 10 with a 12-episode run. Hiiro Ishibashi plays Fushigi Senno, Jun Fukuyama plays Jimmy, Saori Hayami plays Himitsu, and Nobuhiko Okamoto plays Blue Umbrella Man. Yuki Inaba directs at Studio Palette and handles series composition, with Kaori Yoshikawa on character design. Shikao Suga performs the opening theme, "Kageboshi."
The staff for Keroro Gunsō, the new Sgt. Frog television anime, streamed a second main trailer on Monday and announced five cast additions: Yuki Sakakihara as Fuyuki Hinata, Minori Fujidera as Natsumi Hinata, Sumire Morohoshi as Momoka Nishizawa, Hiiro Ishibashi as Mutsumi Hojo, and Koko Fukushima as Koyuki Azumaya. The trailer previews the opening theme by ano and the ending theme by PURPLE BUBBLE. The anime premieres October 3 on TV Tokyo.
The staff for the television anime of Kamome Shirahama's Witch Hat Atelier manga announced two new cast members on Monday. Veteran voice actor Ryusei Nakao will voice Sasaran, a member of the Brimmed Cap group, while Hiiro Ishibashi has been cast as Euini. Sasaran appears in episode 10, which aired on June 1, and Euini will join the story in episode 11 on June 8. The two characters play significant roles in the upcoming Second Pentagram Test Arc. Nakao said he was looking forward to the series because he liked its world and became fond of playing a character shrouded in mystery. Ishibashi said he was drawn into the manga's world and felt honored to join a work loved around the world. Ayumu Watanabe is directing the anime at BUG FILMS. The series premiered on April 6 on Tokyo MX and other channels. Crunchyroll streams the anime as it airs, including an English dub. The manga launched in Kodansha's Morning Two magazine in July 2016 and has 16 compiled volumes as of April 2026. The franchise has over 7 million copies in circulation worldwide.