In the December issue of Afternoon
magazine, an announcement will be made that a two-chapter special of the "Mushishi
" manga will be published.
This announcement also includes news of a "top secret project" that is in the works for the series. More info on this project will come via the wraparound jacket band that is included in the deluxe keepsake edition volumes of the original manga. The first and second volumes are expected to ship on November 21, 2013, while the third volume is expected to ship on December 20, 2013. It is not specified which volume this announcement will be included with.
The original "Mushishi" manga was published from 1999 to 2008 and received an anime adaptation
which aired from October 2005 to June 2006.
Source: Scan via earlbox
Mushishi Tokubetsu-hen: Hihamukage