Nanashi's World, known unofficially as World B and the Secondary World, is an alternate world which runs in parallel to the primary world of the author and his three writing partners. It serves as the setting for Bleach: Tower of Night which featured Rōnin Shiba, the alternate counterpart to Kenji Hiroshi, as the primary character. It is also the world where Kentaro Shiba, Kaien Shiba, Fujimaru Kudō, Matsuri Kudō, Miyoko Kato and Shuji Kato originally hailed from.