One thing that comes to my mind is the weather factor, Japan by December is very cold and Ancajas should acclimatised himself otherwise it might affect him in this fight as Pinoys are not used to a very cold weather.
Good catch right there. Extremely cold weather tends to weaken the body of a person who has used to be on a torrid weather.
However, Ancajas might already be in a place where it's close as cold as the winter in Japan. He might have adapted into different kinds of weather especially that he's constantly flying from 1 country to another whenever he has a fight.
Moreover, body conditioning will be they key to eliminate that factor, keep the sweat coming once he steps foot on the ring.
I wont see this to be a big factor that would affect Ancajas performance and yet if we do really count off the duration of the entire round time wont really be that enough on affecting someones condition except on getting exhaustion due to the fight itself.
I agree that they are bit aware of Japans weather condition which a boxer could really have already planned on being able to adapt
yet being a boxer who do flew on different countries would be mainly having this consideration.
The boxers always consider the environment they are in, this is the reason why sometimes they train in the country where the venue is.
They know their weaknesses, so that's the job of their respective coaches, to address those weaknesses before the match.
I guess, I will be betting on the Filipino boxer here. A lot of Filipino boxers are getting famous because of their resilience inside the ring.
Also, take into account that Ancajas is under MP Promotions (Pacquiao's company), which I believe, he is in good hands.
edit : I just read an article that this fight is postponed, so it will not happen at the end of the year. This is owed to new covid restrictions.
https://www.badlefthook.com/2021/12/3/22816367/kazuto-ioka-vs-jerwin-ancajas-unification-officially-postponed-boxing-news-2021