You can quickly look up Japanese zip codes (postal codes). Also you can see the map where you are looking up.
Using the official recently data come from Japan Post Service Co., Ltd.
You can look up by a zip code.
You can look up by an address.
You can look up by Hiragana if you put only Hiragana letters.
This site allow you to look up by alphabet as Romaji.
Note that you can not drop U and O (e.g., toUkyou, kyoUto, hokkaidoU or oOsaka).
If you want to look at the place on the map where you are looking up, click the link at addresses on the result list.