The rebellion begins when Muramasa appears and begin freeing the many Zanpakutō spirits. The Shinigami begin to lose the ability to contact their Zanpakutō spirits. Muramasa leads the spirits to a confrontation with the Shinigami atop Sōkyoku Hill. The Shinigami, now unable to use their Zanpakutō, are unable to deal with their former Zanpakutō, throwing the Seireitei into a state of emergency.