These are incredible novel topics, topics that are quite unlikely to interest a UK or even US reader. But I then realize that Japan is neither UK nor US. Japan is Japan. This is Japan, you once hinted, is a popular saying to justify Japan's weirdness. So, I agree with you on these topics. They could possibly fascinate and enchant a Japanese mind.
So far, I've enjoyed the notes from under your sprawling Tatami mats. Although the notes are largely non-fiction, the storytelling have been great and compelling. This leaves me with the belief that you could make a great novelist if you're ready to invest the time. Moreover, what lured you and your friends to think up novel topics if you never intended to write a novel? Strange.
PS: Much of your writing style reminds me of H. Rider Haggard, the greatest, I believe, British adventure novelist. If you ever make up your mind on writing fiction, I believe you'll do well writing an adventure and in the first person narrative point of view.
In the spirit of the pen,
David.