But I'm interested in the second game can you pick it up and play without having to know the story from the first or is it going to get confusing?

The game has a feature that tells the story so far, and the datalog is pretty extensive I think.

Ah great. Thanks.

Yeah. It's better if you played all the way through, but the game provides you a very helpful overview of events from the first game. And the second game is different enough with its focus on Serah and the new guy Noel that it isn't a big deal. The story doesn't exactly make that much more sense when you understand the first game. It's all about the gameplay and characters. So, if you find yourself confused with something in the new game, it's probably confusing even to those of us who finished the first game. ha. Don't sweat it.

So jump right in to FFXIII-2, good sir!

I only played through half of XIII and have had no problem following what is going on.

It catches you up and then there's the datalog so you should be okay

You could you tube the ending and just carry on over if you really wish too, the end of 13 doesn't really have any cliffhanger, and the game in general doesn't have or leave any questions during the end so might be interesting to know what happens before and after the final boss to understand what 13-2 is talking about since it does reference things that happen during the events of the final fight and why the entire story in 13-2 is happening, so id just catch the ending and be ready.

You might not be able to appreciate the characters and the universe as much, but there is a section in the main menu of the game that gives you a plot summary for every chapter in XIII.