BP-501 Shadow Maru, is a character that appears in the Brave Police J-Decker television series.
Shadow Maru functions as the Brave Police team's undercover investigation unit. He posses multiple forms, including a unmarked police car, a jet, a tank, and a robotic dog, and special technologies that allow him to hack almost any computer system and mask his presence.
He was originally the second unit built, being developed from his older counterpart Kagerou. Kagerou went rogue after finding his memory was going to be wiped. Unfortunately, Shadow Maru was forced to destroy him after Kagerou's Super AI chip was removed and he was turned into a mindless war machine. Shortly after, he was inducted into the Brave Police, where he usually performed undercover reconnaissance work, sometimes partnering with Duke.