A similar phenomenon of culinary appropriation and adaptation might be the Nepali-run Indian restaurants in Japan. In the past twenty years or so, they have spread to nearly every corner of the country. Though independently owned and run, they have largely similar menus, with food that, I've read, would seem out of place in both Nepal and India.
A recent book in Japanese [1] does a good job of tracing their origins and their role in giving immigration and employment opportunities to Nepalis.
[1] https://shinsho.shueisha.co.jp/kikan/1208-n/
Addendum: After I posted the above, I counted in my head the number of Nepali/Indian restaurants within a twenty-minute walk of my home in Yokohama and came up with six (I’ve eaten at all of them). It turns out that there are several more. Here’s a map of my neighborhood with them marked:
https://www.gally.net/temp/20240823_Indian_Nepali_restaurant...
If anyone wants to see what they look like on Google Street View or search for others, here’s a link:
https://www.google.com/maps/search/%E3%82%A4%E3%83%B3%E3%83%...
Probably none of them have katsu curry on the menu, though I have been to a few Nepali/Indian restaurants in Japan that did serve it—no doubt to appeal to less-adventurous Japanese tastes.