I think that's Hashima island, I doubt the Japanese government will sell it. And it would make a poor secret lair since it is not exactly far from Nagasaki, only a few km.
These pictures... Evocative, interesting, and beautiful. A reminder that beauty is all around us, and that once upon a time people strived to make even the most mundane items (like, say, that toaster a page back) into a thing of beauty...
I was pretty sure it was used as a setting in a Bond Film. (( goes to look )) Skyfall ... Daniel Craig era https://www.pri.org/stories/2012-11-23/history-hashima-island-bond-film-skyfall