# Kamen Rider Myce cast and plot details

> Live situation record from CLSTR: https://clstr.news/situations/kamen-rider-myce-cast-announcements
> Updated: 2026-09-04T19:10:00.000Z. Sources: 9. Developments: 3.

Cast announcements have been released for the upcoming Tokusatsu TV drama ‘Kamen Rider Myce’, the eighth installment in the Reiwa Kamen Rider series. The series is scheduled to premiere on September 6, 2026, on TV Asahi.

Initial announcements identified Shoei Iwanaga as Vanken (Kamen Rider Vanken), a literary enthusiast representing the Dog in the Zodiac Alliance, and Kasumi Hasegawa as Muton (Kamen Rider Muton), a loyal individual representing the Sheep. Subsequent details expanded the cast to include Rento Nishiyama as Kei, the Rooster representative of the Juunishi Alliance, and Hirofumi Suzuki as Ende, the Monkey representative and a scientific researcher. Additionally, Hiroshi Shirakuma was named as the voice for Ryuzu, the Dragon representative.

The plot centers on Sora Otosumi, played by Ikuhu Akiya, who uses ‘Ride Eggs’ to transform into Kamen Rider Myce to fight mysterious monsters called ‘Fukashigi’ that prey on humans. Otosumi is described as a dedicated butler serving a prestigious family. The series introduces the ‘Juunishi Alliance’, an organization that has awakened from a 100-year slumber to protect humanity. 

In the debut episode, titled ‘Rat! The Meister and the Young Lady’, the protagonist protects high school student Yuna Mizuho. Akiya noted that his character possesses a dual nature, balancing a dignified butler persona with a wilder side during combat, often maintaining a relaxed, ‘effortless’ demeanor.

## Claims

- Kamen Rider Myce is the eighth Reiwa-era Kamen Rider series. (corroborated by 3 sources)
- The protagonist, Sora Otosumi, transforms into Kamen Rider Myce, which is themed after a mouse. (corroborated by 3 sources)
- Rento Nishiyama will play Kei, the youngest member of the Juunishi Alliance representing the Rooster. (corroborated by 3 sources)
- Hirofumi Suzuki will play Ende, a member of the Juunishi Alliance representing the Monkey. (corroborated by 2 sources)
- Hiroshi Shirakuma will provide the voice for Ryuzu, the Dragon member of the Juunishi Alliance. (corroborated by 2 sources)
- The series features monsters called 'Fukashigi' that prey on humans. (corroborated by 2 sources)

## Timeline

### 2026-09-04: Kamen Rider Myce series to premiere with Ikuhu Akiya

The new series ‘Kamen Rider Myce’ premieres September 6, following butler Sora Otosumi as he fights mysterious monsters using egg-shaped transformation items.

4 sources. https://clstr.news/cluster/kamen-rider-myce-series-to-premiere-with-ikuhu-akiya

### 2026-08-23: Kamen Rider Myce cast announced for 2026 series

Cast members Rento Nishiyama, Hirofumi Suzuki, and Hiroshi Shirakuma have been announced for the upcoming Tokusatsu series ‘Kamen Rider Myce’, set to debut in September 2026.

5 sources. https://clstr.news/cluster/kamen-rider-myce-cast-announced-for-2026-series

### 2026-08-16: Kamen Rider Myce announces new cast members Shoei Iwanaga and Kasumi Hasegawa

Shoei Iwanaga and Kasumi Hasegawa have been cast as new riders in the upcoming series ‘Kamen Rider Myce’, set to premiere in September 2026.

3 sources. https://clstr.news/cluster/kamen-rider-myce-announces-new-cast-members-shoei-iwanaga-and-kasumi-hasegawa

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Cite as: Kamen Rider Myce cast and plot details. CLSTR, https://clstr.news/situations/kamen-rider-myce-cast-announcements