Actually, there is a good reason why it is called “Nippon” (or “Nihon”) in Japanese and “Japan” (or similar words) in English and other languages of the world.
If you are at all familiar with the Japanese language, you perhaps know that the Japanese use a few types of letters – hiragana, katakana, and kanji (Chinese characters). Chinese characters are a kind of *ideogram*. “Ideogram” refers to letters that represent the meanings, while alphabets represent the sound.
It is well-known that Marco Polo introduced Japan to the Western World, and he called Japan “Zipangu”. He wrote that in Japan there was gold everywhere, but he actually never traveled there. He went only to the southern part China.
In Japanese, “Nippon” is written as 日本. 日 means “Sun” or “Day” and 本 in this case represents “origin”. Chinese people called it so because Japan is located in the East and literally is in the direction where the sun rises (in other words, where the sun originates). That is why Japan is sometimes called “the country of the rising sun”. In modern Chinese, 日本 is pronounced Ribén (Mandarin Chinese pronunciation). However, and very interestingly, in the days of Marco Polo and even nowadays, in the southern part of China, 日本 was pronounced as Ji-pang or Zu-pang. He called Japan “Zipang” because people in the south part of China told him about the country of the rising sun and the term they used to refer to it. This is how Marco Polo brought the name “Japan” to the Western World.
More interestingly, the Japanese normally have more than a few ways of pronouncing one kanji, which is an ideogram. 日 is also pronounced “Jitsu” as you see in the word 本日(honjitsu), meaning “today”. 本 is pronounced “hon” or “pon”, so if you combine the two alternative pronunciations of these words, it will become “Jitsu Pon”, which sounds very much like “Japan”, “Zipang”, or “Japon”.
The truth is quite simple.