That having been said, it's a fairly basic question that Hazō would easily know the answer to. @eaglejarl would Hazō expect that this course of action would be treasonous to Leaf and/or Fire?
Short answer: Yes.
Long answer: See the quote of
@MMKII 's post below and my comments in response.
Sure, but you must concede that the technical legality is ultimately irrelevant? It doesn't matter if we break laws, it matters if we get caught and punished for them.
+1 Insightful
There are multiple ways one could frame this as "Fucking over the local yakuza." without adding "...and in a way that explicitly benefits the other yakuza." at the end of it. Since the yakuza are criminals, we have de facto authority to pretty much execute them on sight if we felt like it, barring standing orders to the contrary.
Mmmmm...so-so. The Yakuza occupy a slightly muddy position in the criminal world. They are useful to the Hokage/Daimyo in that they serve as an ersatz police force by keeping the even worse people in line. As known quantities, they know they're easy targets if anyone in the ninja hierarchy decides to come after criminals, so they have incentives to keep ninja from needing to do so. In a sense, the profits they extract can be viewed as their payment for this service.
If you catch a low-level Yakuza thug (or any other civilian, for that matter) in the process of committing a serious crime such as arson, stealing from or inconveniencing ninja, or interacting with foreign powers in any fashion...chop away. If they're doing something minor, like beating or killing another civilian, then you can chop them, but it's considered something like "My friend and I were walking to lunch and he stopped to pick up and throw out a bunch of litter that someone dropped." No one is going to complain, but they'll look at you funny and maybe roll their eyes.
When dealing with higher-level Yakuza, that's something that should end up in front of the Hokage. If you kill one of those guys, you will need to offer an explanation.
You might question the difficulty of doing so undetected, but thats another argument.
Remember: one of our main antagonists and forces of opposition is now the tinpot dictator of the country we reside in, and on the books is our commanding officer. Pretty much everything we can do to undermine or depose his authority would be considered "treason" or "illegal" in some way by today's standards. Those labels aren't reason to immediately bin any plot or plan bearing them.
+1 Insightful
Hm. I don't suppose I can convince you to go back to the original version of "researching doesn't eat time slots from an action plan in the same way training doesn't, provided you only do one of them", can I? Changing it to need specific dedicated time in an action plan sounds like it's going to heavily incentivise either greatly increased lighthousing (making things less interesting for the QMs) or greatly decreased research (making things less interesting for the players).
I don't think there's any especially workable way to write this - if Hazou's going to be doing research, it's going to have to fit into the story realistically. He can't go on a weeklong Uplift mission *and* spend a week on research, or spend all day negotiating a truce with Hiashi *and* spend all day researching.