In the movies, or rather, in the good movies there is an international man of mystery. The character is either a good guy or a bad guy, sometimes the line is blurry and past events lead to a shocking ending that everyone kind of already knew about thanks to Internet spoilers.
Leo is that man. He's a rough agent - in that he also wears a suit to non-work functions. He gets laid like crazy and has a cult-like following on the Twitter and the Google Plus.
It's also worth noting that Leo is satire. I'd leave this part out, but apparently there are some really stupid people in this world who honestly get upset when it isn't made crystal clear that such things are jokes. Oh well.