It's a Rumic World: 50th Anniversary Weekly★Shonen Sunday

Alright, this thing is only three minutes long, so naturally this review is going to turn up short also.

Story: Skipped

This anime was created to promote the OVA releases of Urusei Yatsura, Inuyasha, and Ranma 1/2 respectively. Of course, it's all one-hundred-and-ten-percent fanservice, but if that's not why you're watching it, then what are you expecting? The entire reason "Rumic World" exists is so that you can experience the novelty of Ranma misunderstanding Inuyasha's species, seeing Inuyasha attack Lum, believing her to be some sort of demon, and, of course, to see Ataru flirt with every female character that showed up for the crossover, including ... girl Ranma.

Art: 9

The animation is great, of course. They'd have to be pretty lazy to neglect filling something this short with eye-popping moments of art, each of it staying true to Takahashi Rumiko 's art style (for example, when Ranma punches Amaru in the beginning, you can plainly see Amaru's fingers doing the Spider Man pose as he flies away.)

Sound: 7

I don't remember much of the music, but the voice acting was pulled off at the expected level. Everyone sounds great. Nothing else to say here. Moving on.

Character: 8

The characters act exactly as you would expect them to, and in humorous ways, almost like the crossover is natural to them. They all look as great as they did in their series. Presumably. I admit, though, at only having watched Ranma 1/2 so far, so I'm not entirely certain.

Enjoyment: 9

Finally, this really is enjoyable to the point where I was fairly disappointed when it ended. Of course, there isn't enough time for the gimmick to wear off, so the "OMFG INUYASHA VS. ATARU" stays strong throughout.

Overall: 8

If you like even one component of Takahashi's work, then watch this. If you've never heard of Takahashi Rumiko before (the wealthiest female comic artist in the world) then this would serve as a fantastic introduction. If you hate her beyond all measure, then why not watch it anyway? It's less than three minutes long, so it won't exactly kill you. I give this my general recommendation.