Splinter's sensei, Mogo-san, has come to New York and asks for Splinter's help in stopping the Black Heart Gang, which is led by Mogo-san's grandson.
Tropes
- Gang of Hats: The Black Heart Gang is a street gang that happens to dress like ninjas. The fact that their current leader comes from a Ninja clan makes for an adequate explanation.
- Good All Along: It turns out that Yoku hasn't turned to a life of crime. In fact, he is a US government agent who infiltrated the Black Heart Gang to undo their criminal activities from the inside.
- Remember the New Guy?: According to Splinter, Mogo Yoku was with him when he moved to America, but this is the first time we ever hear of him. Even the Turtles knew about him.
