To prepare for the great battle to come, Sora and Riku have been
summoned to take the Mark of Mastery exam and become full-fledged
Keyblade masters. This time, their journey will take them through the
Sleeping Worlds, where they must find the seven Keyholes to gain a new
kind of power. But not long after their test begins, the two friends
find themselves separated, journeying through different versions of each
world. What's going on? And what awaits them at the end...?