Strike Witches from Gonzo
I don't even know where to begin. The level of ecchi-ness in this show is off the scale. At first glance it appears that there's a bunch of girls (very young looking, though some are probably older than they're drawn, which tends to happen in these sorts of shows for...various reasons) running around in very, very short skirts. But in fact, many of them seem to be wearing shirts, and no pants at all. Although in the case of the really young girls, they appear to be wearing a sort of swim suit type thing under their school uniforms. In other words, there are an unnecessarily ridiculous amount of pantie shots during the show.
Now that that's out of the way....
A Strike Witch is a witch (they're all female, it seems) that the Britannian government uses to fight the war against the Neuroi. The witches' magical powers combined with a machine called a Striker Unit (that attaches to their legs like boots) allow them to fly and wield weapons ordinary humans cannot. But it's not all big guns and destruction (although there's plenty of that) - whenever the girls activate their magical powers, they sprout a pair of fuzzy ears and a tail.
Yoshika Miyafuji is a young witch and a powerful healer. Her scientist father disappeared some time ago after going abroad to Britannia, where he invented the Striker Unit. Major Mio Sakamoto arrives to recruit Miyafuji for the Strike Witches, but she resolutely refuses to participate in war. She would much rather serve in her family's clinic and heal people. However, soon after their meeting, Miyafuji receives a letter from her father that includes a picture of him and (a younger) Sakamoto standing next to a Striker Unit. Believing her father to have been dead, Miyafuji rushes off to find Sakamoto and insists she be allowed to travel to Britannia to look for her father, but still refuses to fight in the war (though she does express a desire to be useful on board the ship). Unfortunately, on their sea voyage to Britannia, the fleet is attacked by Neuroi units.
Watching the opening animation for the show gives you a pretty good estimation of just what sort of show this will be. The Strike Witches are shown flying around shooting down large planes with equally large weapons, their shirts flying open and their skirts blowing up to reveal pantsu and more pantsu. I don't know; perhaps their lack of pants allows them to jump into and use the Strike Unit easier? Maybe there simply isn't a realistic reason, but it certainly makes me feel a little better to think otherwise. The animation is good at least.
Miyafuji (center), Mio (left) and Perrine (I think) in the image above.