She gained incredible kicking and jumping power from an accident, and as such this is her Buster Power. Her powers have a trade-off however. Her weakness is that if she runs out of calories for her "inner battery" to burn, she will be unable to move. Thus, she compensates by eating lots of candy.

13 years ago, when Messiah was newly created, it trapped the scientists and Buddy Roids into a small room. Yoko was among the trapped, as her mother was one of the scientists. After the head scientist teleported the facility to a dimension in hyper-space, Yoko, Ryuji, and Hiromu, as well as the Buddy Roids, were left behind. The little girl broke down, distraught that she had lost her mother.