Japan is known as a highly ethnically homogeneous country. About 98% of the population is Japanese. The language spoken in Japan is mainly Japanese.
However, the situation has changed these days.
First of all, more and more Japanese people are interested in foreign cultures and languages. Even though Japanese is our native language, the number of people who speak English is increasing so that English is becoming our second language day by day. Some Japanese studies foreign languages other than English. Similarly, as for culture, Japan has been adopting various foreign cultures.
In addition, I think the percentage of foreigners in Japan will increase in near future. As the older population of Japan is becoming a problem for Japan. I think, due to this, there is or will be a shortage of workers in some industries. As a result, Japan might accept more immigrants in the future.