The Teenage Mutant Ninja Turtles pursue the evil cyborg genius Dr. WhereWhen through a time portal...and emerge in feudal Japan! There, they encounter Usagi Yojimbo, 20 years into the samurai's future but decades after the arrival of Dr. WhereWhen... who has already carved himself a fiefdom using mechanized clockwork samurai robots... with the intention of conquering both the past and current timelines!