To try and dig up the weirdest anime of all time wasn't easy, but this one comes close, lets see how long I last before I go into hysterics.
Here is the review for Butt Attack Punisher Girl Gautaman

Mari Amachi starts at a new school named Perfect Religion Academy but all is not well when the Black Buddha Gang kidnap her roommate. To stop this sinister evil, Buddha himself appears before Mari and offers her a special sumo thong that transforms her into the hero Gautaman.
Using her special wedgie powers she fights to save her friends and protect the freedom of religion.
This is a real 45 minute ova series, she saves the world by fighting with her butt and gets stronger when the sumo thong tightens. She catches swords with her butt, for some reason Darth Vader is in it......
*Technical Difficulties one moment please*
Cut me some slack, I watched this with my sister over some Long Island Iced Tea, I'm still racking through my brain the insanity of this show, I've got no more to say, this show is unreviewable.
Final Verdict: If you belong to an Anime Society or frequently band together for marathons then watch this as the final show of the evening and see how weird the Japanese can get.