In a dark future where New York has fallen under the control of the Foot Clan, only one of the four Teenage Mutant Ninja Turtles is still alive. Older, alone, and deeply scarred by the loss of his family, he returns to the city with one goal: to end the rule of those who destroyed everything he loved. Armed with the techniques and weapons of his fallen brothers, the Last Ronin begins a mission of revenge that forces him to confront his past, his failures, and the few remaining allies still capable of resisting those in power.