With Bob Arum as his promoter, expect Inoue to conquer the higher division just like what Manny Pacquiao did in his prime but of course with the help of Bob Arum. Maybe his fight with Butler if pushes through will be his last in the bantamweight division and then move to the 122 lbs limit and see what the future would give to this Japanese superstar.
Yes, Naoya Inoue is vocal about moving up a weight class. If he wins against Paul Butler there's nothing left now to do in the BantamWeight Division. Another rising-star Asian contender in the World of Boxing is in the making because of Naoya Inoue's dominance. Paul Butler is just lucky to have a shot at Inoue. That will be a dream match for him and I don't really see how can he counter Inoue's speed and strength like what Pacquiao is showing during his BantamWeigt period.
Donaire already achieved a good boxing career. He will recognize as one of the good PH Boxers in history. The time now to consider calling it a career.