The Last Ronin: The Lost Years is a new and crucial step in the construction of the "Ronin-verse" of the Ninja Turtles. It is both a prequel at the hit The Last Ronin, explaining what Michelangelo did in the years following the death of his brothers; and a future-oriented follow-up, which shows the arrival of a new generation of Ninja Turtles, who will have a lot to do to walk in the footsteps of their elders.