Of course there’s been a lot of cross-fertilization in recent years; but overall are there any broad differences in theme or outlook reflecting uniquely Japanese or uniquely Western perspectives?
Because of Hiroshima and Nagasaki, nuclear weapons carry a huge stigma in Japanese stories. Nukes are either a sign of pure evil intent, or an ultimate last resort.
Planet-cutting death rays or turning earth’s entire populace into tang is okay, though.
There is a visible lack of large-eyed teenage girls in very short schoolgirl uniforms in American SF.
Ive started mentally adding about five years of age to ever character in Japanese scifi. A sixteen year old controlling the army’s most advanced mecha? No way, he’s 25!
Forgot to mention that there is also a visible lack of pretty teenage boys who snog each other at every opportunity in American SF…