Dr. Slump: Arale-chan - episode 26 - 20 Oct, 1981

Dr. Slump fits a miniature spy camera in Arale to survey her activities and get a glimpse at Miss Yamabuki's panties. His plan works, but Dr. Slump proceeds to make a video recorder and sends Arale to take a bath with Miss Yamabuki, so he can record a video of Yamabuki's naked body. This does not work out for him with Arale being distracted and Donbe makes Dr. Slump's plan backfire. (Source: Wikipedia)