The left half of Double providing the 'body' and a self-dubbed Hardboiled Detective. Shotaro is also a Kamen Rider on his own as Kamen Rider Joker
The right half Double, providing the 'mind,' he disappeared after being broken down into data but came back a year later, thanks to his mother and sister
Kamen Rider DoubleEdit
When Shotaro and Philip set their Gaia Memories into the Double Driver Belt, Philip's conscious mind enters Shotaro's body to produce Double. Their quote at the start of a battle is "Now, count up your crimes!" (さあ、お前の罪を数えろ！, Saa, omae no tsumi o kazoero!), a quote originally used by Sokichi Narumi.
When combined as Double, Shotaro usually does most of the talking, though both speak when saying their pre-battle quote and announcing Maximum Drive attack names. When Philip speaks by himself when transformed, Double's right eye flashes. Double's ability to function is dependent on the condition of both Shotaro and Philip. If their synchronization is somehow disrupted, Kamen Rider Double will be unable to move properly. If their Rider form takes any damage at all, both of them will feel the pain after returning to normal and Philip will often pass out due to his weaker constitution. Shotaro's habit of flicking his wrist carries over to Double.
Kamen Rider Double is unique among Kamen Riders in that rather than having explicitly defined forms, he instead has mix-and-match powers. Through the different Gaia Memories, Double has access to various combinations of powers, weapons, strengths, and weaknesses. Kamen Rider Double's forms accessed through their first six Gaia Memories are known as Half Changes (ハーフチェンジ, Hāfu Chenji), due to the fact that Double can switch out one (or both) Gaia Memories in the belt in a Memory Change (メモリチェンジ, Memori Chenji) to change forms.
Each different version of Kamen Rider Double has its own finishing attack(s) known as Maximum Drives ( マキシマムドライブ, Makishimamu Doraibu which is needed to defeat a Dopant. The energy imparted by the Maximum Drive does not destroy the Dopant but rather its Gaia Memory, resulting in the ejection of the Gaia Memory from the user's body and the destruction of the Gaia Memory, hence why such a procedure is called a "Memory Break" (メモリブレイク, Memori Bureiku
- Rider Height: 195 cm.
- Rider Weight: 85 kg
- Punching Power: 2.5 tons
- Kicking Power: 6 tons
- Maximum Jump Height: 60 m.
- Maximum Running Speed: 100 m. per 5.2 sec.
- Joker Extreme: 12 tons
CycloneJoker (サイクロンジョーカー, Saikuron Jōkā) is the primary form used by Double, first seen in All Riders vs. Dai-Shocker and the first form utilized within the television series. It is colored green and black from the Cyclone and Joker Memories, hence known as the "Fast Skilled Warrior." This form's finishing move is a drop kick Rider Kick called the Joker Extreme (ジョーカーエクストリーム, Jōkā Ekustorīmu), during which Double's body splits down the middle as the halves descend on their target. A variation of this attack involves Double jumping off the back wheel of Kamen Rider Accel Bike Form, allowing for faster acceleration upon descent.
- During the events of Shotaro's jidai geki-influenced dream, the Gaia Memories are replaced by wooden placards known as kifuda (木札) and uses the Japanese pronounciation of the Gaia Memory names or synonyms; thus, this form is dubbed as ShippūKirifuda (疾風切札; Whirlwind/Trump card). During the transformation, kabuki makeup-like patterns appears on Shotaro's face.
- Rider Height: 195 cm.
- Rider Weight: 98 kg.
- Punching Power: 5 tons
- Kicking Power: 5.5 tons
- Maximum Jump Height: 49 meters
- Maximum Running Speed: 100 m. per 6.5 sec.
- Joker Grenade: 15t
HeatJoker (ヒートジョーカー, Hīto Jōkā) is the first Half Change form used by Double when he appears in the Kamen Rider Decade film. It is colored red and black form accessed from the Heat and Joker Memories, hence known as the "Hot Skilled Warrior". In this form, Double can throw flaming punches by means of the Heat Memory's powers. The form's Maximum Drive finisher is the Joker Grenade (ジョーカーグレネード, Jōkā GurenēdoRider Punch, during which Kamen Rider Double somersaults in mid-air, then HeatJoker's body splits down the middle during descent as the halves each hit the target with elementally energized hooks.