Hmmm, alright let's see here... what's this anime about? Let's try to piece it together from what we know. Let's see, there's the name. We know the name. It's called Full Metal Panic... and it's an anime. So, the Full Metal part of the name... implies some sort of metal... metal usage... metallic... mechanized metallic man... giant robot! Okay, probably some sort of giant mecha robot thingy.
And the Panic part of the name... what does the panic mean? Panic because of... some sort of inner turmoil? Panic because of... inner turmoil... at being... an effeminate man? Some sort of androgynous effeminate looking guy. And who tends to panic? Perhaps a female... of... youth? Female youths tend to panic. And... let's see, female youths go to... school. Schoolgirls. Schoolgirls in uniforms.
Alright, I think I've pieced this mystery together.