Is there a missing part of The fast and the furious movie sequel?

As I understood the fast and the furious 4 is a prequel to Tokyo Drift where we can see that Han is still alive and he mentioned something about things happening in tokyo but what about Fast 5? Why is Han still alive there? What really happened in Tokyo after Dom made his appearance in the last part of the movie? The maker of this movie is making me crazy, they focused mostly in the cars chasing each other that they sometimes forgot to supplement the details of the story. I hope in the upcoming sequels if there still are, this will be clarified, or maybe you guys can help me figure this out.