Actor: Ulf Ōtsuki
Professor Harley Hendrickson is an American scientist who is the creator of Mach's technology, as well as Krim Steinbelt's teacher. He also lends hints for Rinna Sawagami to help her develop the Trailer-Hou for Drive Type Formula. After the Special Investigations Division is disbanded, Harley finds Go walking on foot to return to America, and picks him up to take him along himself. This eventually leads Go to accept Harley as a family, finally understanding that the concept doesn't only apply to bloodlines alone.