What does Japanese Japanese II mean?

The so-called Japan 1 generation refers to Japanese who have been designated to live abroad (mostly immigrants in the past) and obtained local nationality. Common are Japanese Americans and Japanese Brazilians.

Then the second generation of Japan is the next generation of the above-mentioned people, and the next generation is the third generation. The second and third generations were born and raised in the local environment, so their language and thoughts are almost the same as those of the locals, and they almost lost their ability to speak Japanese. The more the next generation, the more obvious and common this phenomenon is.