|This article is about a/an web episode in Kamen Rider Zi-O.|
Mystery of Naming (ネーミングの謎 Nēmingu no Nazo) is the first episode of Kamen Rider Zi-O: Supplementary Plan. It was released on TTFC accompanying the first episode of Kamen Rider Zi-O, and is referred to as "episode 1.5" of Zi-O.
What is the mystery behind the names of characters appeared in first episode? There are some answers...
Sougo, Tsukuyomi and Geiz received a script and started to talk about the naming. Sougo figured out [Oma Zi-O]]'s Oma is a reversed spell of Demon King (魔王(マオー) Ma Ō) and Zi-O is "King of Time" (時の王 Toki no Ō). Zi also represents 20, means he's the 20th Heisei Kamen Rider. Tsukuyomi figured out her name is based on a Shinto moon deity. However, in Geiz's turn, he can not find any information from his script. While he's in confusing, Woz showed up and told him Geiz means "King" in their series. It is a pun on English word "Gates". And in Japanese and Ancient Egyptian culture, Emperor of Japan (Mikado) and Pharaoh both having "gate" etymologies. Yet, Tsukuyomi pointed out it should be "Gate" in the English grammar, making Woz start complaining that the Toei staff are lazy and explained they put an "s" is actually for good toy sales superstition.
- 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)
- Woz (ウォズ Wozu): Keisuke Watanabe (渡邊 圭祐 Watanabe Keisuke)