All Japan
All Of Japan
expression
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).
ぜんにほん
ぜんにっぽん
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.
これは、全日本バレーボール大会のしあいの写しんです。
This is a picture of a Japanese National Volleyball tournament match.
コウイチは、けん道の全日本せん手けんのしあいを見るために、日本に行っています。
Koichi is in Japan to watch the All Japan Kendo Championships.
全日本が生クリームに包まれている。
All of Japan is covered in whipped cream.