Monthly Shōnen Jump
The first chapter was released in 2001 in "Monthly Shōnen Jump", but afterwards the chapters were released in the "Weekly Shōnen Jump" on a monthly basis due to the discontinuation of the prior magazine. The manga was later serialized in the "Jump Square" magazine, Shueisha's replacement for the "Monthly Shōnen Jump". 155 chapters in all were released in Japan. An anime adaptation of the manga was announced in the October 2006 edition of "Monthly Shōnen Jump". The first episode of the anime aired on April 3, 2007 on Nippon Television, with the last one shown on September 25, 2007.