List of Kamen Rider Decade characters

The characters of Kamen Rider Decade exist amongst various iterations of reality within the series referred to as an A.R. World (Another Rider's/Alternate Reality World).

The Hikari Studio (光写真館, Hikari Shashinkan) is the photography studio that the Hikari family owns and where Tsukasa Kadoya develops his photographs. The various backdrops located in the studio allow it to transport its occupants to a mutltitude of parallel worlds. Its interior and exterior automatically transform to blend into the surroundings when moving across dimensions.

Tsukasa Kadoya (門矢 士, Kadoya Tsukasa) is an arrogant, young man without any memory of his past. As a photographer, his photos never come out right, which is later revealed to be a sign of his world being slowly destroyed by the convergence of the other Kamen Riders' worlds. To save his world, he transforms into Kamen Rider Decade (仮面ライダーディケイド, Kamen Raidā Dikeido).

Tsukasa Kadoya is portrayed by Masahiro Inoue (井上 正大, Inoue Masahiro). As a child, Tsukasa is portrayed by Riku Ichikawa (市川 理矩, Ichikawa Riku).

Natsumi Hikari (光 夏海, Hikari Natsumi), referred to as "Natsumikan" (夏蜜柑, Natsumikan, Summer Mikan) by Tsukasa, is a young woman who works at the photo studio under her grandfather, having lived with him since her childhood. . Prior to the series, Natsumi was a member of the Taigaku Club (退学クラブ, Taigaku Kurabu) or TG Club (TGクラブ, Tī Jī Kurabu) for short, a group of dropouts who got bored with school and wanted to find out their own answers. But they never carry out their intent and return to school, promising to meet again years later. At the start, Natsumi begins to have nightmares of Decade prior to finding Decade's belt and giving it to Tsukasa. Fully aware of world's endangerment, Natsumi decides to accompany Tsukasa on his journey to prevent her dream from coming true.

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