As far as Asian countries are concerned, Japan has fewer immigrants to the USA than Philippines, China, Vietnam, Korea, and India. But Japan sticks out despite the relatively low migration rate.
* The USA in general does have a sense of "the importance of the foreigner" or outsider. Foreigners invite new thought, new culture, and new experiences.
* Japan seems to make an ideal outsider. They're physically on the other side of the world. Their history is basically isolated from "The West" for hundreds, or even thousands of years.
* Yet, with all of that, modern Japan has integrated very finely into the culture of the West. Japanese brands are well-liked (Nintendo, Sega, Sony, Mazda). And as far as I can tell, Japan also likes a number of USA brands (KFC, Pizza Hut, 7-11, Disney, Levi Jeans, McDonalds, Star Wars).
* The media empire of Japan (not movies necessarily, but Japanese anime and Japanese video games, which are popular in the USA) has a lot of synergistic play / counterplay with USA. For example, the "RPG" genre has been shaped by both cultures heavily. While the USA can claim the big-daddy Dungeons and Dragons, as well as Rogue, Diablo, Bauldur's Gate (Canada, but still "Western"), World of Warcraft, and Skyrim... Japan has the Final Fantasy series, Dragon Quest, Legend of Zelda (including Breath of the Wild). There's a lot of influence and synergy between the "JRPG" and "WRPG" genres.
In short: Japanese culture is both familiar and foreign.
Cowboy Bebop is perhaps the best example of what I'm going for. Its a hardcore scifi space opera filled with Jazz: the American-influence on the anime cannot be ignored. But its still an anime with big eyes and the unique "Japanese" drawing style.
The familiarity allows American audiences a degree of comfort, while the Japanese tropes entice us with their exoticness. Its both familiar and different.
And from my understanding: the opposite occurs in Japan. The Jazz and "Americanisms" in the anime are designed to give a bit of an exotic feel for Japanese audiences and entice them. While the Anime tropes are there to give them familiarity.
And that's why its synergy. Familiar to us is exotic for them, and vice versa.
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EDIT: And then there's "Power Rangers", the weirdest thing to ever happen between the USA and Japan. Its neither fully American nor fully Japanese. Its clearly "Super Sentai" footage, but the "American Parts" with Johnny / Kimberly / Jason are still core to the series.
Its not just "Power Rangers" either. Transformers, and Sonic. Sonic is a Sega-owned video game character... but a lot of the animation was... American/France. How's that for a change? Outside of the "Sonic X" anime--- Sonic SatAM, The Adventures of Sonic, Sonic Underground, and Sonic Boom are all primarily animated in the West. With the comics done by Archie.