Isn't that what most sequels are anyway ?
A continuation of the original story? Sometimes it happens in a different places, with different characters, and other stuff. But essentially every sequel is a continuation of the same original concept.
Which in this case I would be fine with.. I would like a Sequel that delves deeper into the roots of where Saya and her race came from originally, as well as what happened with Haji, what Nathan's plans for the future are, and some background on Nathans past too. How does Saya react when she wakes up? Is Haji there to help restore her memory or is she like she was before, when she woke up and had no clue who she was?
What was the political fallout in the world? How has the power structure changed, did anyone reveal the United States' implicit connection to the corpse corp program?
How are the twins raised? Do they exhibit odd powers? Do they also fall into periods of hibernation or does it not come on until a certain age?
Does Kai ever find a woman he can settle down with? How does he cope with raising the twins? Does red shield take care of his financial security? Does it even still exist? Does the dumb ho that chased him across the world with the reporter, whom she then ran off with, get guilty and try to get Kai back?
There are plenty of legitimate things to explore in a sequel, however the intention to be true to the original story and its contiuation, and to exploring the new characters, as well as further exploring old characters, has to be at the heart of the project.
