in one of the dreams before the ending, Ataru ends up dressed as Frankenstein's Monster. Two scenes of the film are referenced: the "birth" of the monster in the lab and when the Monster meets the young girl near the river.
The opening of this film is almost a shot-for-shot remake of the opening scene of the second Urusei Yatsura film, substituting the Urusei Yatsura characters with the Ranma 1/2 characters.
