Shiro

"You...why must you make Sora sad?"

- his words to Den-O regarding a saddened Sora

Shiro (死郎) is a man who attempts to alter time to switch the worlds of the living and the dead through the Ghost Train (幽霊列車) as Ryotaro Nogami's abduction allows it to traverse time like the DenLiner. He has an obsession with Sora and cannot bring himself to do anything that he perceives would make her cry. Shiro is a master of necromancy and can revive both Imagin and humans alike.

Battle with Den-O
Kamen Rider Yuuki Hijack Form is a very powerful Rider. Yuuki summons all of the past Imagins Den-O defeated during the TV show. Momotaros, Urataros, Kintaros, Ryutaros, Sieg, Yuto, and Ryotaro transform into their respective riders. Yuuki retreats by horse as Sword Form and Liner Form give chase. As Yuuki stops at a battlefield, he turns around, knocking the two Den-O forms off their horses. As Yuuki makes his final move, Teddy arrives and stops him from doing that. Kotaro arrives and transforms into Kamen Rider New Den-O Strike Form. After a sword battle, Den-O Sword Form and Liner Form grab onto Yuuki's arms. New Den-O activates Full Charge, and while he does that, Sword Form and Liner Form activate their Full Charges, powering up their swords. The Riders defeat Yuuki and Shiro slowly dies, while Sora stays by him saying her final words as she leaves in the Ghost Train.

Hijack Form
"Hijack Form!"

- Transformation announcement

Ability perimeters
 * Rider height: 199cm
 * Rider weight: 107kg
 * Punching power: 7.5t
 * Kicking power: 9t
 * Maximum jump height: 40m
 * Maximum running speed: 100m/5s

Hijack Form (ハイジャックフォーム) is the form of Kamen Rider Yuuki that Shiro accesses on his own. Hijack Form has a black and red color scheme, compared to Skull Form's black and gold color scheme, lacking the skull-theme. Hijack Form also performs the Terminate Flash, but does so with his Savage Gasher (サヴェジガッシャー) sword.

Amadum
Amadum, the ruler of the world within the Magic Stone with a penchant for dressing as past villains fought by Kamen Riders, appears in Shiro's costume in The Kamen Rider Rings.

Portrayal
Shiro is portrayed by Yu-ki Matsumura (松村 雄基). As Kamen Rider Yuuki Hijack Form, his suit actor is Kazutoshi Yokoyama (横山 一敏).