In his author's note section of the March issue of Kadokawa Shoten's Young Ace magazine, Yoshiyuki Sadamoto reported last Friday that he will do best to release the 13th volume as planned this year. The 13th volume will be the first new volume in two years. However, neither Sadamoto nor Kadokawa has confirmed that the 13th manga volume is still the final one.
Sadamoto resumed the manga last April after a 14-month hiatus, and the 90th chapter ran in the most recent issue with a "to be continued" note. Kadokawa published the 12th volume in March of 2010, and Viz Media published the 12th volume of the manga last February in North America.