I know that the first manga came out on June 5, 2012, and the anime came out on October 9, 2012. But with production times taken into account was the idea made in let's say 2010 and then the manga was just produced first and the anime followed.
Or was it a that the anime was already in production and they made the manga to get the interest for the anime when it came out later? A silly question but if anyone knows that would be interesting to hear.