Full Name: Tsukumaro "Shirogane" Oogami
Ranger Designation: GaoSilver
Title: Sparking Wolf
Weapons: Gao Hustler Rod
Gear: G-Brace Phone
Special Attacks: Evil-Crushing Sacred Beast Orbs, Evil honorably defeated, Silver Wolf Full Moon Cut
Power Animals: Gao Silver, Gao Hamma, and Gao Ligator
A thousand years ago, GaoGod was defeated by the extremely dangerous Hyakkimaru, a fusion of the Highness Dukes. Shirogane, which means silver in olden days, was part of the Gao Warriors and often played his flute along with the priestess, Murasaki's beautiful voice for the Power Animals, especially Gao Deer. In desperation, Shirogane donned the Dark Wolf Mask of Loki, which would give him the extra power he and the Gao Warriors need to defeat the mighty Org. Despite the frantic warnings of Murasaki, that the mask would possess him, he donned it even though he knew what would happen anyway. The evil energy referred to as the "Evil of A Thousand Years," contained within the mask gave him the ability to combine his three Power Animals into GaoHunter. He lasted long enough to defeat Hyakkimaru, then the mask transformed him into Loki. He begged the other Gao Warriors to stop him while he still had a vestige of control, so they sealed him within a tomb.

Centuries later, he was released from his seal by Ura to fight against the present day Gaorangers. Although he is initially considered evil as Loki, he does showed aspects of his true self, such as tending the wounds of Sae and helping an injured wolf cub. He would snap into his human form occasionally, one time Kakeru spotted him bathing naked with the cub. To prevent him from remembering the past, Uraimplanted a bug into Loki's head which would further cloud his memory, and strengthen his resolve in destroying the Gaorangers. By this time, the Gaorangers had already figured out Loki's true identity, and sought a way to restore it. GaoGod's spirit appeared to Loki a couple of times, to try and make him remember his past. GaoGod even created an eclipse to cut off Loki's power source, and allow the Gaorangers to reach through to Loki for a brief period. Neither plan worked, and Loki returned, still seeking vengeance. To break the spell over Shirogane, Gao Hunter needed to be defeated in battle. To accomplish this, the Gaorangers were assisted by Gao Rhino and the Gao Majiro. With these new Power Animals, they formed the Gao King Striker, which was able to take down the Gao Hunter, scattering its Gao Jewels.

Once the mask was destroyed and the evil energy was released, he was returned to his human form known as Tsukumaro Oogami. He later risked his life by taking on the Chimera Org to get back the Gao Jewels he had stolen as Loki. By fighting with all of his strength to save the Gaorangers from Chimera Org, his Power Animals rewarded him with the G-Brace Phone that would allow him to transform into GaoSilver. He killed Ura, when he came back in his 'Ultimate form' and he had a personal grudge against Silver. Afterwards, he spent most of his time trying to make up for his past sins against the Gaorangers. He was very distant towards the Gaorangers and declined Kakeru's invitation to move into Gao's Rock with the others. Instead, he stayed in the pool hall, Billiard Jack. Shirogane used the Gao Hustler Rod as one would use a pool cue to send his three orbs into battle or formation. However, he didn't actually know the game, and has been taken under the tuteledge of a bartender, Billiard Master who saw his potential. He was reluctant to accept help from the other Gaorangers during his battle with Loki, but he opened up once GaoWolf led the others to him and he realized that the others trusted him despite the things he did while he was Loki. When Gao Deer came to the Gaoranger's attention, he declined to help because he was angry with Shirogane because he held him responsible for Murasaki's voice being damaged. Murasaki took an attack meant for Shirogane from red Orgettes and her throat was hurt, unable to sing. Shirogane made it up to Gao Deer by having Tetomu sing along with his flute playing. He also has the ability to detect Org disturbances from the winds. After the final battle, he returned his G-Brace and jacket to Tetomu, he traveled across the nation alone although he initially planned to travel with Sae.

Later in 'Hurricanger vs Gaoranger', he came to help his former Gaoranger team members, Hurricanger, Goraijer and Shurikenger for help and defeated Tsuetsue and Yabaiba and the Jakanja. He was dressed as a nomad and had traveled throughout the planet on Gao Wolf in his Wolf Roader form.