1.) You don't hold a drawn bow like that that long (for good reason, doing so is exhausting and will cause muscle fatigue and shaking very quickly, even if you're an archer used to higher draw weight bows). Granted, we're not talking about a high poundage warbow here, but still. You can draw it in the blink of an eye and loose it. You're not going to miss at that range, either.
2.) Eminent domain. Virtually every country has it. And given how Japan treats rights of citizens as... suggestions... rather than hard set things and what their police alone can get away with doing to you, I wouldn't be surprised if they had the legal authority, somewhere and somehow, to just take the island seeing as it is Japanese soil.
3.) Politician being there "officially unofficially" is dumb and provides absolutely zero plausible deniability and her being a megacunt and calling people "peasants" is hilarious even by manga bad guy standards. (Bonus points for her asking him to throw in the elf with the purchase like he was a farm animal or something. Seriously, what was going through that woman's head?)
4.) The guy is a millionaire. He can hire a security company even if his eroelf wasn't enough.
Ironically, the dumb politicians dumbfuck antics in being there "officially unofficially" like that and being that much of a piece of shit could turn public sentiment against the government if it went viral. And you could easily make a bigger deal out of it than the Japanese government would rather deal with by appealing to the United Nations, America, The Hague/ICJ, anyone that you could get the attention of.