All Of Japan
You know 日本 means "Japan." So, now you have the kanji for all added to it, making this word All Japan (as in "All Japan Railways" or something like that).
You know the reading of 日本. Now just add the on'yomi reading of 全 and you should be able to read this word.
The population of all of Japan is mainly Asian.
The All Japanese women's volleyball team is good.
Mt. Fuji is popular among all the mountains in Japan.