, pronounced "beat X" and stylized as B'T X, is a manga series, written and illustrated by Masami Kurumada. It was serialized in "Shōnen Ace" from 1994 to 2000. The series is set in a fictional universe where science has progressed to the creation of mechanical AI creatures known as Bt's. An anime adaptation containing 25 episodes was aired in Japan between April and September 1996, followed by a sequel containing 14 episodes called which was made between 21 August to 20 November 1997. The anime series strayed off from the manga series in "Neo," giving its own conclusion to the show.