User blog comment:Pauldin91/About Momonosuke.../@comment-24850639-20161212190022

I'm not against the thought of him joining, and think he does mesh well enough with the crew for it to be a likelihood, but I just can't imagine how the scenario happens. Yes Momo is the Daimyo of Kuri, but is that truly a position that he can actually serve as a child? At his current age he is nothing more than a prop, a symbol of the importance of the position. With that said, the cases for him staying in the country and leaving with an eventual return are just as strong IMO. Him being there can serve as a huge morale boost for the country, as well as helping to change the country's overall opinion of pirates and allowing visitors for the foreseeable future. His dad had a vision for the country, and naturally Momonosuke should be the person to see that vision through. Momonosuke and the Kozuki family's relationship with Luffy will go a huge way.

On the other hand, Kin'emon, Kanjuro, and Raizo will be probably be the ones actually doing the most of the work both after Kaido's defeat, and during, when they're trying to convince the other samurai to let the Straw Hats help. I can see sense in letting Momo explore the world and learn more about his abilities under the tutelage of the Straw Hats, and then coming back to run his country when he's matured enough and seen more of the world. In ch 818 (or 819 could be wrong) when Momo has that flashback of what happened to his parents, his dad apparently says something to him about understanding the world better. I can see this going either way, but for right now I want to vote on him staying in the country after the Kaido business is dealt with.

Btw, this discussion is super early, if anything, Momo wouldn't be making this decision until after Kaido is down for good, and that could be 150+ chapters from now.