Prediction,

This is a good fight.
Higa is a monster, 15-0, stopped everyone, only 22, already a world champion, making his third title defence, I think Higa has a future in top level boxing, boxing needs more top fighters in the lower weight classes!, so fighters like Higa, Inoue, Taguchi, they are very good for boxing.

Rosales is a good fighter, never been stopped, he is a former international champion, he has won country titles and Latino title fights, he has experience, he is a good opponent for Higa, but also, a live opponent in his own right. Rosales last lost back in May, when Andrew Selby (Olympian, then 8-0) beat him, he dropped Selby, but lost everything apart from that. Rosales has lost 2 other fights, he lost to Kal Yafai on points in 2015, and there was one very early career defeat.

I think Rosales is good at a certain level, but at world level, not so much, and I think the calibre, the outstanding power of Higa is going to be enough for the champion to retain his title. I have never seen him fight, but I assume Rosales has good general ring experience, can do the rounds, can take punches, gets stuck in everytime he fights, but I wouldn't assume he is a good defensive fighter, and I think fighters who are good at taking punches, when they step up, fight an opponent with power like Higa, they are only more open to shots, and they get hurt, take a beating like any other opponent.

I think Rosales might be able to soak up a lot of Higa's punches for 3 or 4 rounds, fire back, but Higa's shots will take a toll, the difference in levels, and tne damage will be clear to see by round 5, I think Rosales will become an easy target, and I would be surprised if he got past round 8.
I think Higa stops Rosales in 6-8.