I love this anime. I also find it incredibly frustrating at times. Hear me out. There is far too much inappropriate fan servicing going on with the half-dressed characters and all the groping that occurs. The plot and dialogue can be messy and make no logical sense. And yet. And yet. Despite all of it's flaws, I've been hooked since the first episode of the first season. I don't really consider there to be four seasons as 'season 2' is four episodes long and more like a mini... not spin-off, but not really anything serious enough to drive the overall story along. The characters can be quite fun, I love all the ridiculous overpowered action, and there are some surprisingly touching moments throughout the series. It's definitely my guilty pleasure and if you're looking for something fun to watch, this would be my vote.