Project ARMS Vol 9

From the VIZ Media edition

The Arms Kids' quest to uncover the truth about their past takes them from Japan to a cowpoke town in Arizona called Gallows Bell. There, they come face to face with an elite group of special forces called Team Epsilon. Ryo and the others soon learn that this viciously wicked squadron hasn't earned its nickname "Genocide Force" for nothing. To make matters worse, enter a new enemy Arms called "The Mad Hatter" with powers that verge on the sublime.

Source: Anime News Network Encyclopedia