B'T X

Teppei, having trained for eleven years with Karen, sets out to visit his older brother Kotaro Takamiya at a scientific conference. His reunion is violently interrupted when a woman named Aramis attacks the conference, killing everyone and kidnapping Kotaro. Determined to save his brother, Teppei's journey takes an unexpected turn when he encounters B't X, a broken mechanical horse. Through a mysterious connection, Teppei's blood revives B't X, and the two become allies. Now, Teppei and B't X must confront the enigmatic Machine Empire, the organization responsible for Kotaro's abduction, and navigate a world of advanced technology and hidden dangers in their quest for rescue.