Cassette Tape Garakuta-dori no Stain : Season 1 Episode 6

Stain and Palvan obtain a mystical cassette tape and use it, along with other spare junk to construct a robot. The robot's only desire is to dance to the tune of the tape and it uses Palvan and Stain as non-stop dancing partners. Unable to bear the dancing robot, the two must fix the situation before the robot discovers its ability to display anger.