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Shiro Mizuki (水城 史朗, Mizuki Shiro) was a soldier who became the main user of the G4 system, becoming Kamen Rider G4 (仮面ライダーG4, Kamen Raidā Jī Fō, Masked Rider G4), one of the primary antagonists of the movie Kamen Rider Agito: Project G4.
History[]
Kamen Rider Agito: Project G4[]

Mizuki in the G4 armor with the suit's creator Risa Fukami.
He was one of the military personnel guarding the GA psychic educational facility during the time it was attacked by the Formica Pedes. Though he would survive the ordeal, he would be left a jaded man.
With his pride as a soldier shattered, Mizuki began living as one who would embrace death as the true means of becoming stronger. He would eventually volunteer as the operator for the G4 exo-suit and, as fate would have it, clash with G3-X operator Hikawa, to put their ideals to the test on the battlefield. But throughout the course of the battle, the G4 system begins to suffer malfunctions.
Despite this, Mizuki refused to surrender. In the end, Mizuki would succumb to the strain placed upon him by the G4 system and die. The G4's AI attempted to rise and continue the battle, but was destroyed by Hikawa.
Kamen Rider Decade[]
Rider War[]

Kamen Rider G4 appears with other Kamen Riders commanded by Wataru Kurenai ,but all are
murdered by Decade in the episode 1 of Kamen Rider Decade in the dream of Natsumi Hikari and then conclude the dream with Decade as only Rider in the Rider War [Rider War]
The World of Kuuga[]

Kamen Rider G4 with the other Riders appears when Natsumi remenbers the dream of the Rider War, the dream ends with the shock of fists between Decade and Kuuga .
[The World of Kuuga]
The Destroyer of Worlds[]

All the Riders killed by Decade.
In the special version of episode 31, Kamen Rider G4 is seen as one of the many Kamen Riders who fought in the Rider War against Decade and were all destroyed. They were presumably restored after the destruction (and subsequent revival) of Decade at the end of the Rider War and the worlds were restored. [The Destroyer of Worlds]
Episode Yellow: Treasure de End Pirates[]

During the events of Episode Yellow: Treasure de End Pirates, Kamen Rider Diend Complete Form summons G4 alongside seven other Movie Riders using the Attack Ride Card Gekijouban to defeat Kamen Rider G Den-O. Here, G4 uses Gigant , possibly in order to better go along with the other Riders' ranged finishing moves (as occurred with Kamen Rider Glaive's Gravity Slash).
Kamen Rider Heisei Generations Forever[]

Kamen Rider G4 appears as a toy, when Sento Kiryu and Sougo Tokiwa they find Ataru Hisanagahe brings them to his room which is filled with Kamen Rider memorabilia, with Sougo and Sento stunned to see toys of themselves. Ataru reveals that Kamen Riders are fictional.[Kamen Rider Heisei Generations Forever]
Appearances in other media[]
Kamen Rider Decade: All Riders Super Spin-off[]
That One! Jiro Okamoto: Final Blow Diet!![]
Kamen Rider G4 appears cited as example of the riders that portrayed the Suit Actor Jiro Okamoto with Caucasus, Ryuga, Odin, Nega Den-O, Leangle, and Black. Later he does not appear in the quiz with the other Riders.
OOO, Den-O, All Riders: Let's Go Kamen Riders: ~Let's Look! Only Your 48 Riders~[]
Type14. - Grandma's Lucky Food![]

Kamen Rider G4 appears with Stronger, Accel, and OOO Latoratar Combo. According to Momotaros, G4 is considered the devil rider.[Type14. - Grandma's Lucky Food!]
Type44. - Quietly Listen! Underwear, Myself and Underwear[]

Kamen Rider G4 appears with Kaixa, X, and TheBee Masked Form. According to Sieg, G4 is considered a lover for women.[Type44. - Quietly Listen! Underwear, Myself and Underwear]
Video Game appearances[]
Kamen Rider Agito video game[]

In the Kamen Rider Agito game for the Playstation, while G3/G3-X has limited fighting time and will instantly K.O after the time is over, G4 doesn't suffer that limitation, possibly because G4 is a more advanced version and has successfully eliminated the weakness of G3/G3-X system.
Kamen Rider Battle Ganbaride[]

Kamen Rider G4 with G3 ,G3-X and G3 Mild appears as a playable character with other Kamen Riders of Heisei and Showa Era in this video game Kamen Rider Battle Ganbaride.
Kamen Rider Riderbout[]

G4 as seen in Kamen Rider Riderbout
Kamen Rider G4 appears as a playable character with the other Heisei and Showa Kamen Riders in Kamen Rider Riderbout.
Kamen Rider Batton-Line[]

G4 in Batton-Line
Kamen Rider G4 appears as a playable character in Kamen Rider Batton-Line among other Riders in the game.
Kamen Rider Battride War II[]
G4 in Kamen Rider Battride Wars II.
G4 reappeared in Kamen Rider: Battride War II as a boss fighting against Kamen Rider Agito and Kamen Rider G3-X, G4 is a Rider who is good at long-distance attacks, including continuous fire attacks with the modified GM-01 special weapon type. He also uses the Gigant missile launcher. In addition to shooting directly, he also shoots around himself.
Kamen Rider Battle Rush[]
Kamen Rider G4 appears as a playable and support character in the video game Kamen Rider Battle Rush using Gigant.
Kamen Rider Transcend Heroes[]

Kamen Rider G4 appears as a playable character with other Kamen Riders in the video game, performing his Gigant against his enemies Kamen Rider Transcend Heroes.
Kamen Rider Buttobasoul[]

Kamen Rider G4 is a playable character with other Kamen Riders of Heisei-Era , Neo-Heisei-Era, and other monster and Villians in Kamen Rider Buttobasoul.

Kamen Rider G4 Medal
Masked Rider Expansion[]

Kamen Rider G4 Masked Rider Expansion card
Kamen Rider G4 appears as a playable character in this trading card game with other Kamen Rider Kamen Rider Heisei-Era, Showa-Era, Super Sentai, Metal Heroes, and other Heroes.
Personality[]
After being saved by Hikawa during the raid of Formica Pedes, Shiro's personality had taken a warped fixation on the concept of death. He believes that strength comes from embracing death, where one no longer clings to life as a whole, whether it be the lives of others or their own. This new Consequentialist-esque view in strength had warped his morality, not being afraid to sacrifice the life of Mana and not feeling lost over the deaths of his own men who had previously worn the G4. It is believed that the reason he clings to death as he fights is due to his failure in protecting the facilitators, children, and his comrades during the raid, as he once had shown doubt both in his views and in his actions after Hikawa's speech about his views on life.
Abilities[]
Skills[]
- Advanced Military Combat: Being a mercenary, Shiro advances the mercenary martial art. This leads Shiro able to be a perfect balanced fighter
- Peak-human Durability: As the candidate user of G4, Shiro held the longest duration for able to survive on using G4 before the system's weakness was covered with an esper like Mana Kazaya.
Weakness[]
- G4 A.I.: As mentioned by Sumiko, G4 was designed as too powerful for human usage. Using the G4 System for prolonged periods would eventually lead the user to be taken over by its A.I. post-mortem and become completely vulnerable to any attack.
Kamen Rider G4[]

Kamen Rider G4
- Rider Statistics[1]
- Rider Height: 198 cm
- Rider Weight: 187 kg
- Rider Senses[1]
- Eyesight: 15 km
- Hearing: 15 km
- Ability Parameters[1]
- Punching Power: 4 t
- Kicking Power: 13 t
- Resistance: Hardness 10
- Maximum Jump Height: 25 m
- Maximum Running Speed: 100 m per 7.5 seconds
- Special Attacks
- Gigant: 30 t[2] x 4
Generation 4 is the successor to the G3-System. It was conceptualized by Sumiko Ozawa based G3-X. However, the system was deemed far too dangerous for use, so Ozawa never included the adjustments in the design schematics. However, Risa Fukami would steal the plans and construct the G4 System herself, adding a Prediction System to improve the AI. G4 is much stronger than any iteration of G3. However, its advanced AI causes it to suffer similar issues to G3-X.
Kamen Rider G4 has the following parts:
- Red Eyeser (MDSS・Ver3) (レッドアイザー(MDSS・Ver3), Reddo Aizā (MDSS・Ver3)) - The sensitivity of the lens of the previous MDSS is adjusted to high and the strength of the lens is also improved. Visibility is 3 times than that of the previous version.
- Perfector (パーフェクター, Pāfekutā) - It produces oxygen from water when underwater, decomposes and filters carbon monoxide and poisonous gases when in a fire, and supplies fresh oxygen to the user. This allows G4 to operate in various environments.
- Generator Buckle (ジェネレーターバックル, Jenerētā Bakkuru) - A fixture that connects the Power Converter Lung and the Turtle Shell. Inside is a pipe for circulating energy.
- Power Converter Lung (パワーコンバーターラング, Pawā Konbātā Rangu) - The power source of Kamen Rider G4 with a built-in small high-power generator. The electrical power supplied from the battery is converted to an output several times more powerful.
- G4 Mark (G4マーク, G4 Māku) - A crest that shows Kamen Rider G4 is operated under the jurisdiction of the SDF.
- G Buckle (Gバックル, G Bakkuru) - Kamen Rider G4 power gauge. It displays the power consumption of the battery on the back and flashes violently when the charge remaining is less than 1 minute. In addition, the “energy volume” on both sides can temporarily increase power.
- Weapon Attachment Point (ウェポンアタッチメントポイント, U~epon Atatchimento Pointo) - A connector on the right hip for the Gigant, it connects via a cable and supplies power to the weapon.
- Energy Volume (エナジーボリューム, Enajī Boryūmu) - Servo meters have been strengthened to 2.5 times than that of Kamen Rider G3 and can withstand impacts when jumping from a helicopter in the sky.
- G4 Jacket (G4ジャケット, G4 Jaketto) - The bodysuit. A soft material that has the toughness to repel bullets as well as providing excellent heat and cold resistance via electronic control.
- Power Armor (パワーアーマー, Pawā Āmā) - High metal protective pad. It is about 5 times stronger than special duralumin steel. The left Power Armor is labelled "G4".
- Arms Mount (アームズマウント, Āmuzu Maunto) - A holster for weapons. There is an electrode point to directly charge the weapon.
- PLSS (Ver 3) - A dial that can be turned to control the electricity supply and send an electrical signal to the Gigant to release the launch lock.
Appearances: Project G4, Decade Episodes 1-2, 31 (Special Version only) , Treasure de End Pirates, Heisei Generations FOREVER (as a toy).
Equipment[]
Weapons[]
- GM-01 Custom Type 4 - A modified version of the Kamen Rider G3's GM-01 "Scorpion"; a modular magnum pistol, stored on right hip, hand-carried in use.
- Gigant - A shoulder-mounted missile launcher, mounted over the right shoulder when in use. Used as a finisher.
Rider Cards[]

Kamen Ride: G4

G4 as summoned by Diend Complete Form.
- KamenRide: G4 (カメンライドG4 Kamenraido Jī Fō): A Rider Card containing the power of Kamen Rider G4, possessed by Kamen Rider Diend. It one of the eight cards used by Diend Complete Form. It summons Kamen Rider G4. [Episode Yellow: Treasure de End Pirates]

AttackRide: G4 Gigant
- AttackRide: G4 Gigant (アタックライドジーフォーギガント, Attakuraido Jī Fō Giganto): The Gigant AttackRide Card is used by Decade to summon Kamen Rider G4's Gigant to attack enemies. Used to defeat Kamen Rider J. [Kamen Rider Decade: The Last Story]
Behind the scenes[]
Portrayal[]
Shiro Mizuki was portrayed by Ryo Karato (唐渡 亮, Karato Ryō). As Kamen Rider G4, his suit actor was Jiro Okamoto (岡元 次郎, Okamoto Jirō).
Concept Art[]
Notes[]
- Unlike the majority of Heisei Dark Riders, who are counterparts with the Primary Rider of their respective series, G4's counterpart is the Secondary Rider G3-X.

G4-chip in Kamen Rider Decade
- G4's chip appears in the Kamen Rider Decade series. The chip was found in Shoichi Ashikawa's old locker by Daiki Kaito. The chip, however, was destroyed by Tohko Yashiro.
Appearances[]
Kamen Rider Agito
Kamen Rider Decade
- Episode 1: Rider War
- Episode 2: The World of Kuuga
- Episode 7: Super Trick of the Real Criminal (Flashback)
- Episode 14: Super Den-O Beginning (Flashback)
- Episode 31: The Destroyer of Worlds (Special Version only)
Episode Yellow: Treasure de End Pirates
OOO, Den-O, All Riders: Let's Go Kamen Riders: ~Let's Look! Only Your 48 Riders~
Kamen Rider Heisei Generations Forever (as a toy)
See Also[]
- Makoto Hikawa - Kamen Rider G3-X, who utilizes a more advanced version of G4 in Project G1.
References[]
External Links[]
- Shiro Mizuki in Kamen Rider Official Website
- Kamen Rider G4 in Kamen Rider Official Website