關智一
A web-based radio program for the series aired in Japan. Hosted by Tomokazu Seki and Hikaru Midorikawa, the program included mini-stories and special guests discussion the series. The program was released across two CDs in Japan by Geneon Entertainment. The first was released on May 25, 2007 with the first seven broadcasts and a bonus track. The second CD, containing the remaining six broadcasts and a bonus character song, was released on October 24, 2007.