also: にっぽんいち
noun, noun which may take the genitive case particle 'no'
Japan's best; number one in Japan
Used to describe something or someone that is the best, largest, or most outstanding in Japan. Can function as a noun or as a prenominal modifier with の.
富士山は日本一高い山です。
Mt. Fuji is the highest mountain in Japan.
彼は日本一のピッチャーだ。
He is the best pitcher in Japan.
Standard kanji spelling. The reading にほんいち is the most common.
Alternate reading, often used in formal or patriotic contexts, or in proper names.
世界一 means 'the best in the world', while 日本一 is limited to Japan.
Compound of 日本 (Japan) and 一 (one, first). The reading にほんいち is the standard combination; にっぽんいち uses the alternative reading of 日本.