Do you think they'll ever make a second series?

I doubt there will be more made. It seems to be trend to convert the first few books into an anime and just stop. I've seen this with a lot of shows. I've also discussed with friends as to why we think it is they're doing this...

I personally think it has to do with the wishes of the author. What better way to sell more books than to withhold the rest of the story?

There is also the partial truth which is... most of these shows come out before the series are complete. This can lead to the series ending rather abruptly ( Loveless, Air Gear ), or massive amounts of fillers ( Naruto, Bleach ).

Personally I'd rather a series ended abruptly than being splattered with useless filler episodes.

Either way it is unlikely they will do a second series, unless the book itself has gargantuan amounts of sales. In comparison Air Gear one of my favorite manga/anime is insanely popular... but they have never continued to make the anime..

Just read the books. It'll be the best you can get I think.

I also think this is a rising trend fans will just have to grow accustomed to... Some television shows just don't make it, same as here as it is there. I can imagine if the anime doesn't get the ratings they want could also be a reason why they wouldn't continue to green light the show.

Just something to think about.

I need to be myself, I can't be no one else - Noel Gallagher