|This article is about a/an web episode in Kamen Rider Zi-O.|
The Secret of Fourze 555 (フォーゼ555の秘密 Fōze Faizu no Himitsu) is the sixth episode of Kamen Rider Zi-O: Supplementary Plan. It was released on TTFC accompanying the sixth episode of Kamen Rider Zi-O as its "episode 6.5".
Recapping the latest episode, Sougo wonders why Another Faiz appeared in the Fourze Arc. Tsukuyomi and Geiz come out and explain that actors Fukushi (Gentaro) and Yoshizawa (Ryusei) were busy filming the new Bleach movie.
Takumi Inui, who suddenly appears and introduces himself, claims that Fourze is actually a reference to 555, as Kamen Rider Fourze's two legs and right hand have symbols of χ, Δ and Φ, respectively. As Geiz asks about the square symbol on Fourze's left hand, Masato Kusaka suddenly appears and rejects Takumi's claim. According to Masato, Fourze's setting in a high school is a refer to the Ryusei Private School, which was created to find the Orphnoch King. He also claims that Fourze includes "Ou" in his name, which means "King", so it is fitting for both of the series to appear together in a series about a king like Zi-O.
As Takumi and Masato reject each other's claims and start arguing, Tsukuyomi says they are nothing like Fukushi and Yoshizawa, so three of them decide to go watching their movie. Takumi and Masato, upset for being left behind, discover that the script was made by producer Shirakura, so they state that this is another one of Shirakura's faults.
- Sougo Tokiwa (常磐 ソウゴ Tokiwa Sōgo): So Okuno (奥野 壮 Okuno Sō)
- Geiz Myoukouin (明光院 ゲイツ Myōkōin Geitsu): Gaku Oshida (押田 岳 Oshida Gaku)
- Tsukuyomi (ツクヨミ) : Shieri Ohata (大幡 しえり Ōhata Shieri)
- Takumi Inui (乾 巧 Inui Takumi): Kento Handa (半田 健人 Handa Kento)
- Masato Kusaka (草加 雅人 Kusaka Masato): Kohei Murakami (村上 幸平 Murakami Kōhei)
- to be added
- Actors Sota Fukushi and Ryo Yoshizawa are mentioned in this episode as well as the film Bleach which features both actors. However, the actors' name and the movie are censored.
- As Geiz is talking to Tsukiyomi about this, he and Sougo strike the poses of the characters the two actors are playing.
- Takumi and Masato blaming Shinichiro Shirakura for bad scripting is possibly a reference to the general hatred of him by the fans for his executive involvement many Kamen Rider productions, most notably the retool of the second half of Kamen Rider Hibiki.