Mirai Shishiō

Tsukasa's younger sister. Height: 139 centimeters. Born on December 31st. Blood type O.

At the age of six, she fell into a state of clinical brain death with no possibility of regaining consciousness. She was kept alive by life support, and Tsukasa became a martial artist to cover the costs, eventually being called the strongest primate.

Senkuu proposed to Tsukasa that they use the revival fluid to bring her back and cure her brain death as a ceasefire deal. Her stone statue was buried underground near the Tsukasa Empire and was discovered by Tsukasa. The revival fluid cured her brain death, and upon seeing her brother after a long time, she remarked that he looked older. Unlike her brother, she speaks in what seems to be a Kansai dialect, but the detailed reason for this is currently unknown.

Her mind remains as it was when she lost consciousness at six years old, but she has begun to rapidly mature as she engages in work within the kingdom.