I'm going to preface this by saying that before I watched this particular anime I was not a huge fan of Mech driven anime. However, this series totally changed my view. Heads up though this series may cause some major brain pain due to spatial time issues but its totally worth watching. I don't wanna spoil too much so will stick with the basics. This particular series follows the adventures of Simon the digger. The series starts off on a space ship and then jumps to an underground village where we first meet Simon. About half way through the first episode a Giant Mech crashes through the roof of Simon's village.This is your introduction too Gunmen in the series. From this point on things get strange and are one fast paced battle after another. Throughout the series you are introduced to a number of characters (some of them being rather scantily clad). With the introduction of these characters you'll meet people that you think are villians and people you think are good guys. However I'm going to tell you now that things are not quite what they seem in this anime. Anyways overall this is a fantastic anime and if you haven't watched it what are you waiting on? Even if you're like I used to be and hate mechs this series is definitely worth watching so go watch it.