The two suits were identical except for a few minor differences. Alternative Zero's suit had blue accents and silver cables while Alternative's had orange accents and black cables. Alternative Zero was also decorated with silver stripes labeled "Trial Prototype-00" on both sides of the body. Because they are modeled after crickets, the Alternatives resemble the older Kamen Riders such as Kamen Rider V3 and Kamen Rider Super-1 in terms of appearance.
Alternative and Alternative Zero's true identities were, respectively, Hajime Nakamura and Hideyuki Kagawa. Along with Kamen Rider Tiger, the two were fighting to close the Mirror World and opposed Shiro Kanzaki's Rider War.
Those original series of Alternative Zero and Alternative were both killed the same way - Tojo betrayed them and destroyed their decks, causing them to dissolve in the Mirror World.
Kamen Rider Decade
In Kamen Rider Decade, Alternative is a Dark Rider who is appeared in the World of Negatives alongside Ryuga, Orga, Dark Kabuto and Dark Kiva. He was later destroyed by Kamen Rider Diend.
- Hajime Nakamura (Alternative from original series)
- Hideyuki Kagawa (Alternative Zero from original series)
- Tanaka (World of Negatives' version of Alternative Zero from Kamen Rider Decade)
- An army of twelve Alternatives led by Kagawa/Alternative Zero appeared in the S.I.C. Hero Saga story Kamen Rider Ryuki: World of If.
- Yui Kanzaki (S.I.C. Hero Saga story Kamen Rider Ryuki: World of If.)
The Alternative's sole contract monster is Psycorogue resembling a humanoid cricket which had the ability to transform into a motorcycle named Psycoroader through the use of the Wheel Vent Advent Card and during the Alternatives' Final Vent Dead End. This Mirror Monster had an opposite color scheme to its corresponding Rider, having white armor with black accents. Its name is a portmanteau of the two words, psycho and koorogi, which is Japanese for "cricket".
Because they were designed by Kagawa and not by Shiro Kanzaki, the Alternatives' Advent Cards differ from the ones used by the Kamen Riders. The terminals and images are printed crosswise, having the inscription Alternative Advent Card Alchemy System at the back. Also, there are green characters on the cards, which may give information to the Visor on what kind of card is swiped.
Slash Visor: The Alternative system's card reader is mounted on the wielder's right forearm, with a female voice unlike the male voice used by the Kamen Riders's Visors. Unlike the regular Visors, the Alternatives swiped their Advent Cards across their Visors (much like the Rouzers used in Kamen Rider Blade), which burned up with jet-blue flames and disappeared at the card's scanning.
- Advent (AP: 6500): Summons Psycorogue.
- Sword Vent (AP: 2000): Conjures the Slash Dagger.
- Accele Vent (AP: 2500): Increases Alternative's movement speed.
- Wheel Vent (AP: 4500): Transforms Psycorogue into Psycoroader.
- Final Vent (AP: 8000): Executes Dead End. Psycorogue transforms into a motorcycle, then Alternative and motorcycle spin-out faster and faster until they ram into the opponent. Only Alternative Zero performed his Final Vent. Alternative was killed before performing it.