Long ago in a distant land, I, Aku, the shapeshifting master of darkness, unleashed an unspeakable evil. But a foolish samurai warrior wielding a magic sword stepped forth to oppose me.
Before the final blow was struck, I tore open a portal in time and flung him into the future, where my evil is law. Now the fool seeks to return to the past, and undo the evil that is Aku.