It hasn't officially, but whenever something sells this well a second season is inevitable.
BDs for 3rd volume are over 27 thousand, DVDs over 11 thousand. I think the 2nd volume had higher numbers in DVDs. -checks- About 17 thousand for the DVDs.
It's selling like crazy.
Not just that, but all 10 volumes of the manga topped the charts and have been in the top 50 for months now, selling
millions of copies. So, even if the anime wouldn't sell, the manga sales alone would almost certainly guarantee a second season of the anime, it's
that popular.