Namco wasn’t the only video arcade company with promotional robots in the early 1980s. Taito (developer of the original arcade sensation Space Invaders, 1978) created some promotional robots using some of the skills they had learned building arcade machines. In 1983 they built Yumemaru (Dream-maru), a “walking, talking” robot, and what appears to be a guitar-playing “robot”.
Yumemaru was controlled with a remote control joystick, and moved on wheels – its feet would rise and fall to give the illusion of walking. It would also open and close its right hand gripper (the left hand was fixed). Supposedly it could hold a simple chat, but this could not be confirmed. A Japanese blogger going by Naoyoshipapa was able to see one demonstrated up close back in 2005 (a rare privilege), and you can watch his short video clip of it in action here.