Japanese feel compelled to defend their group because a lot of foreigners impose their cultural expectations on them, and misunderstand the intent behind why certain things are done the way they're done. And because they genuinely love their society/culture.

Never met a single far right Japanese nationalist living there over a year. But nearly all looked at the pros and cons of their society, and felt theirs were better than the list other countries had, for providing a life they wanted to live, and don't care about how those align with other countries interpretation of those things.

Your explanation is one I've often heard from people whose main Japanese friends are the "far left" who have spent significant time living outside of Japan by choice, hardly a group that could be said to represent the average Japanese person. Most Japanese also just find emotionally charged complaint to be disrespectful, even if it's not about Japan. There's a lot to learn about the nuances of their culture, a simple explanation is usually very incorrect, and might not even be a contributing factor.

Curious to hear where your explanation of vocal right wing neighbors comes from.