I would like to know of something more ridiculous than Strike Witches. Other animes have a more ridiculous concept because their purpose is to be ridiculous and to make the viewer feel that way (Kill la Kill, Gurren Lagann).
Bratty 14-year-old has to pilot a semi-biological, semi-mechanical giant robot that contains the soul of his mother and occasionally moves without a power source, trying to defeat a variety of weird aliens(?) while struggling with daddy issues. Did we mention that everyone turns into orange tang in one of the most nonsensical anime finales ever?
Well-endowed female personifications of videogame systems duke it out in a magical world of sexy power-up transformations, intensely screwed-up physics and inter-dimensional teleportation.
Lonely teenage boy gets brought back from the dead by a loli necromancer, becomes Zombie Mahou Shoujo, wields a giant chainsaw, sports a frilly pink dress upon transformation, increases his power level by boosting the "fabulous-ness" of his outfit, and fights demons from the underworld. And an entire harem of sexy females moves into his house.
Take your pick. Strike Witches seems pretty normal by comparison, as I said.
But seriously though, why cat/animal ears? Why school swimsuits/undies? Why prosthetic plane legs?
They have to be able to quickly jump into the Striker Units, which means that they can't wear clothing that covers their legs (and the fact that the non-magical women don't wear trousers can probably be chalked up to fashion - and I'm not going to lie, this was obviously done to titillate the audience). The Striker Units aren't prosthetics; they're like... thigh-high mechanical boots. As for the animal ears; they appear whenever the girls perform magic, so they're probably supposed to represent different animal spirits, or something (and they're super-cute).
Like most harem anime, it's sexual. But let me repeat that: "
like most harem anime". As in: nothing out of the ordinary, by anime standards.