Sadaharu

Sadaharu is affectionate, energetic and initially extremely difficult to control. He frequently clamps his jaws around Sakata Gintoki's head and attacks people smaller than himself, behavior that makes Gintoki reluctant to keep him. Kagura's exceptional strength makes her one of the few people capable of physically handling him.

As he settles into the Yorozuya, Sadaharu becomes noticeably more dependable. His biting never disappears entirely, but he learns to cooperate with the group, recognizes their intentions and repeatedly protects them. His intelligence is sometimes underestimated because he behaves like an oversized pet, yet he can understand complicated situations and respond to requests without verbal instructions.

Sadaharu is an inugami associated with attack and destruction. His enormous body already gives him tremendous strength, powerful jaws and enough endurance to serve as transportation for multiple people. He can fight armed opponents directly and is substantially more dangerous than an ordinary animal.

Feeding Sadaharu strawberries and milk triggers a transformation into a much larger horned form with dramatically increased power. His original role as a guardian also gives him a connection to Earth's Dragon Veins and the Altana flowing through them. His counterpart Komako serves the complementary defensive role.

During the Silver Soul conflict, Sadaharu's true function as a guardian becomes crucial when he works to restrain the destabilized flow of Earth's Altana. Maintaining the seal places an enormous burden on his body and leaves him in a prolonged dormant state afterward.

Sadaharu originally lives with the shrine maidens Ane and Mone, guarding the Koryumon together with Komako. Construction of the Terminal over the Dragon Pulse deprives the shrine of its purpose and income, and the sisters eventually become unable to afford feeding such a gigantic animal. Sadaharu is consequently left outside the Yorozuya office, where Kagura insists on adopting him.

His early transformation reveals that he is far more than an unusually large dog. The Yorozuya eventually work with his former guardians to control him, after which Sadaharu remains with his new family rather than returning permanently to the shrine maidens.

Much later, his connection to Earth's Altana makes him indispensable during the planet-wide crisis surrounding Utsuro. Sadaharu uses his guardian abilities to suppress the unstable energy at tremendous personal cost, turning an ability introduced through an early comedy storyline into an important part of the final conflict.

Kagura is Sadaharu's primary caretaker and the person most responsible for his adoption. She names him after her previous pets, rides him frequently and has enough physical strength to play with him without being seriously injured. Their bond becomes one of his strongest attachments within the Yorozuya.

Sakata Gintoki initially objects to keeping Sadaharu, particularly because the dog repeatedly bites his head. Despite their combative routine, Gintoki accepts him as part of the Yorozuya and sometimes takes responsibility for his care.

Shimura Shinpachi regularly feeds Sadaharu and deals with the practical work involved in caring for him, giving their relationship a more domestic character.

Ane and Mone are Sadaharu's original guardians. Economic hardship forces them to give him up, but they remain emotionally attached to him and are relieved to discover that he has found a genuine home.

Komako is Sadaharu's counterpart and fellow inugami. Where Sadaharu represents attack, Komako represents defense, and the two originally guard the Dragon Pulse together.