Proven appeal of subject: Over 50,000 copies of the original novel series have been sold in print. Japanese turnout is strong, with a manga adaptation released in monthly serialisation and multiple anime series.
Artwork: Multiple full-page illustrations (including a full-color fold-out) add extra value and provide crossover appeal with the manga buying audience.
Artwork: Multiple full-page illustrations (3 color, including a two-page spread, and approx. 10 black-and-white per volume) add extra value and provide crossover appeal with the manga buying audience.