Shiva is the younger brother of Sou Mikaido, the former kumicho of the disbanded Hogougumi. He harbored deep feelings for Wakasa, but she chose to become Sou's kage no seisai, a secondary wife. After betraying his brother, Shiva was killed by Wakasa during the final clash between Hogougumi and Garyukai. However, Sakaki secretly transplanted Shiva's consciousness into another man, Misumi Souryou, whose identity Shiva now assumes. Shiki, Shiva's nephew, is trying to recover him.
Fourteen years later, Shiva remains obsessed with Wakasa and is hunting her child. He even created a robot cat named Kali, which has red eyes that glow when it senses Wakasa's descendant nearby. Sakaki mentions Shiva's "Wakasa-themed collection," noting that he "almost lost a finger" while attempting to touch it. Under the alias "Misumi Souryou," Shiva is now affiliated with Garyukai and prefers using a sword in combat, just like Wakasa.
Tsukasa calls him "Sata Gonzaemon" for reasons unknown and describes his eyes as resembling those of a snake. Upon hearing about Misumi's unusual body, Tsukasa jumps to the conclusion that he must be pregnant, considering him an even bigger pervert than she initially thought.
Owing to their family ties, Shiva and Tsukasa are uncle and niece. While still in his original body, Shiva suffered from an unnamed terminal illness and wasn't expected to live past 20. The neglect from Hogougumi, which focused solely on Sou, coupled with Wakasa choosing Sou despite showing kindness to Shiva, drove him to snap and betray them.
After the battle at Megafloat Airport, Shiva confesses to Tsukasa that he had long been indifferent to winning or losing. When Tsukasa shares the contents of Wakasa's DVD with him, Shiva finally finds closure upon learning that Wakasa wanted to help him find peace and never loved Sou. After leaving with Shiki, Shiva agrees to return Misumi's body.
