Another Shinobi

Another Shinobi (voiced by Hideya Tawada) is actually Rentaro Kagura who is a future Kamen Rider known as Kamen Rider Shinobi from the year 2022. His powers however were stolen in 2022 and reduced into an Another Ridewatch, where it made its way to Rentaro of 2019 and turned him into Another Rider.

After being beaten by thugs when standing up for a friend, Rentaro's desire for strength reaches Heure, who imbued him with the Shinobi Anotherwatch, transforming him into his corrupted future self. The Anotherwatch manipulated Rentaro's negative emotions and against his will, forced him to go on a vigilante spree, killing the thugs from earlier before fighting against Zi-O and Geiz. Shinobi was subjected to the White Woz's future manipulation, first attacking Zi-O when he was spirited by his Black Woz and second after being left defenseless against Kamen Rider Woz. Although he was doubted by his actions, the Anotherwatch influences him to become a king and continue hunting earlier thugs. Sougo's words of encouragement, however, reach him, allowing Rentaro to give a futile resistance against Swartz. With the Shinobi Miridewatch obtained, White Woz uses it to assume Futurering Shinobi and destroy Shinobi Anotherwatch and save Rentaro.

After the defeat of Oma Zi-O in an alternate version of Oma's Day, Rentaro became Kamen Rider Shinobi in the year 2022. After Swartz discovers his existence, he steals Shinobi's powers and creates Another Shinobi in 2019, placing Shinobi's existence in jeopardy until Another Shinobi's defeat.

Confirmed by Shinobi Miridewatch and GeizRevive Ridewatch's unaffected existence even after GeizRevive Timeline's negation, Shinobi continues to exist in his own era.

Rentaro is a brave, strong-willed individual who protects the weak from those who misuse their powers for evil in 2022. However, in 2019, he himself is rather weak and willingly let himself be victimized by the people who harassed his friend. This also drove him with the desire to gain the power to get back on those people, which leads to him becoming an Another Rider.

In Rider Time: Kamen Rider Shinobi, Rentaro is shown to be a skilled ninja, all while at first glance under the pretense of being under pressure in order to keep his identity as Shinobi in secret.

Original

 * Ninjutsu: As part of the year 2022's necessity, Rentaro is also trained in the way of the ninja. Being a Kamen Rider, he is comparably superior to his childhood friend Isamichi but was forced to feign being poor at it in hopes of hiding his double life.
 * Flame Technique (火遁の術 Katon no Jutsu): Rentaro summons a stream of flame from his hands, which translated as Flame Ninpo as Shinobi.
 * Body Replacement: Rentaro quickly substitutes himself with another object such as a scarecrow or a ragdoll, allowing Rentaro to flee and/or hide. This technique is also seen used by Woz Futurering Shinobi.
 * Clone Technique (分身の術 Bunshin no Jutsu): Rentaro creates multiple clones alongside him to attack together. They are also able to perform Ninjutsu techniques.

Another Shinobi

 * Ninjutsu/Element Manipulation: Befitting the original Shinobi, Another Shinobi can utilize Ninjutsu at his disposal and manipulate elements.
 * Pyrokinesis: By tapping into the power of flame, Another Shinobi can summon purple fire from thin air, killing his target in a manner of spontaneous human combustion.
 * Hydrokinesis: From his hand, he can launch a stream of purple water towards his opponent. When killing one of the thugs that harassed him earlier, Shinobi generates water from the floor and drowns them quickly.
 * Sand Generation: Used to kill one of his targets while they were driving, Shinobi buries the driver by generating sand within the car.
 * Umbrageous Teleportation: Shinobi can teleport by merging into a shadow and appear in another place from a different shadow.
 * Aerokinesis: Another Shinobi can generate purple cyclones for defensive or offensive means.
 * Fragoportation: The ability to teleport an item away with an explosion, used to intercept a thug that rode a motorcycle.

Arsenals

 * Ninjatō: In a similar vein to his future alter-ego, Another Shinobi wields a ninjatō which he held on a reverse grip. The weapon itself is stored on a scabbard on his back when not in use.
 * Tekkō-kagi (手甲鉤 lit. "back of the hand hooks"): Another Shinobi is also armed with a pair of Tekkō-kagi for combat.

Weakness

 * Manual Reactivation: Unlike Another Riders from the past who only needs a Time Jacker to reactivate their Anotherwatches once, Another Riders from the future need the Time Jacker's help every time they are defeated to revive.

Trivia

 * The monster version of Another Shinobi will be joining the Nightmare family in the near future.