The name of Japan in its own language is nihon or nippon, alternate readings of kanji characters that mean “origin of the sun,” a name given it by China, written 日本. The two names are interchangeable, with nihon being used in everyday speech and nippon used in more formal situations, for example by lawmakers or the straight-laced newscasters on NHK, Japan’s version of the BBC. The first Westerners heard of Japan was through Marco Polo, who wrote about a strange country 1500 miles to the East of China called Cipangu, a place of great wealth where both temples and average homes were made of gold, and where the people were very polite, although they had a strange custom of eating human flesh. The modern name of Japan has been filtered through many other languages, including traders in Malaysia (who called it Jepang), Manchuria (Zeppen), and the Portuguese (Iapan), and first appearing in English as Giapan. For some reason, the Japanese have focused on the version Zipang as a cool, retro early word for their country, and this name is commonly found in books, video games, an anime and manga series, and computer CPU cooler.
(The anime Zipang is really good, by the way, a kind of Final Countdown in which a present-day Japanese ship is sent back to World War II…I recommend it a lot.)