Project Arms (6.6)

Show · 2001 · 2 seasons · Animation, Sci-Fi & Fantasy, Action & Adventure

Ryo Takatsuki learns that his missing right arm is actually an ARMS nanomachine implant from secret genetic experiments, and alongside fellow test subjects Kei Karuma, Takeshi Tomoe, and Hayato Shingu, he battles the creators of the technology, the Egrigori, to rescue his kidnapped girlfriend Katsumi Akagi.

Starring Nobutoshi Canna, Shin-ichiro Miki, Minami Takayama, Yuji Ueda

We don't know where to watch it in the US.