Urusei Yatsura S00 E08 The Electric Household Guard

"Grab her horns and she might just become your darling!"

Much to Mendō’s surprise, his father got him a personal bodyguard who turns out to be the jungle boy Shingo. Now a ninja, Shingo does nothing but irritate his master as he is still brainless as ever and meets Ryōko who decides to use him for her own fun, leading to some delirious disarray.