Sora and Kairi are tasked with visiting new worlds to protect them from the ever-expanding Heartless, working with Donald and Goofy to hone their abilities as Keyblade wielders. At the same time, Yen Sid and King Mickey discover that an ancient evil long thought defeated has returned, and threatens to plunge all worlds into Darkness.

Forget everything you knew about the canonical world of RWBY. The characters you know are not here. The characters you know are switched.