Shiro Driver

The **Shiro Driver** (Castle Driver) is the transformation device used by all of the Riders in *Kamen Rider Jiryuu*. Created in the past by the great wizard Merlin, it uses Beast Hearts as its primary power source to unite the powers of humans and Fable Tails, both figuratively and literally.

## Sound Bytes

* *Unlock!* (Fantasy Doors opening announcement)
* *(Fable Tail's legendary title followed by an animal basis and the Fable Tail's name) (appropriate sound effects) (two-word intimidation phrase)* (Transformation announcement)
* *(animal basis and Fable Tail's name) Unchained Hissatsu Kick!* (Main Finisher announcement)
* *Shinobu!* (Fantasy Doors closing announcement)

## History

In ancient times, the Shiro Drivers were created following the War of Legends by Merlin after the Fable Tails were sentenced to imprisonment. He created gave them to the most powerful of all the Fable Tails: Dragon, Mermaid, Werewolf, and Tengu. He hoped that these four would help restore faith of peaceful relations between mankind and the Fable Tails should the right people free them. While locked within their prisons, Mermaid and Werewolf modified the Shiro Drivers to their personal tastes out of sheer boredom.

## Functionality

**Transformation**

Before a Beast Heart can be used, the **Awakening Button** on it must be pressed to stimulate the respective Fable Tail's power and call it to the aid of the user. The Beast Heart is then placed within the **Docking Gate** by inserting it via a hole on top of the Driver. The actual transformation procedure is activated by opening the **Fantasy Doors**. The magical power of the Fable Tail then flows through the user and spawns a **Fortress Armor** that attaches to the Rider after their **Underbelly** is formed. It should be noted that some of the magic is held back initially in order to prevent the Fable Tail from being fused to the host permanently.

**Finisher**

To activate a finisher, the Fantasy Doors must be closed and then reopened. This retriggers the Shiro Driver's Fable Tail magic release function, but the fact that the user is already in Rider form causes an intentional overload. This unlocks the full power of the Fable Tail to be used in an **Unchained Hissatsu** (Unchained Certain Kill) attack.

## List of Shiro Drivers

* **Shiro Driver-Ishi** (Castle Driver-Stone): The original design of all four Shiro Drivers. While the others were modified into other forms, the belt belonging to Dragon went untainted. Because Merlin's handiwork went untouched, the remaining Shiro Driver-Ishi is the strongest of the four Shiro Drivers and creates the most perfect union of man and Fable Tail. The design is modelled off of a medieval castle, specifically the castle belonging to the legendary King Arthur.
* **Shiro Driver-Kai** (Castle Driver-Ocean): A slightly modified Driver belonging to Mermaid. Because of her loneliness, Mermaid remodeled this Shiro Driver to resemble the oceanside castle she owned prior to the War of Legends.
* **Shiro Driver-Tsuki** (Castle Driver-Moon): A slightly modified Driver belonging to Werewolf. Because of his grief over never being able to change his situation, Werewolf remodeled this Shiro Driver to resemble the castle used by him as a base of operations during the War of Legends.
* *Palace Driver*: While technically one of the Shiro Drivers, this belt was modified by its user to function differently from the others in an attempt to "improve" Merlin's work.

## Users

* Ryuusuke Akagi

Ryuusuke gained and used the Shiro Driver-Ishi after forming his contract with Dragon.

* Isana Mifune

Isana gained and used the Shiro Driver-Kai after forming her contract with Mermaid.

* Kenshiro Tsukino

Kenshiro gained and used the Shiro Driver-Tsuki after forming his contract with Werewolf.