Sadatsugu Nagaishi

永石 定嗣

Trusted friend and confidant to the three sisters, a very good friend of Heinz and his wife. Nagaishi provides detailed information for Cat's Eye's heists and also helps them acquire any hardware and/or other sophisticated equipment that they may need that Ai cannot provide. His background is a mystery but he may have been a member of the Armed Forces as he has some military expertise. (Source: Wikipedia)