Dr. Slump: Arale-chan - episode 9 - 09 Jun, 1981

Arale blabs to Dr. Slump about Miss Yamabuki's strawberry panties. Helped by Arale's animal friends, the professor conducts a complicated scientific process so he can get a peek at Yamabuki's panties. However his attempts fail, leaving him in a state of shock. (Source: Wikipedia)