A posting on TokyoMango with an accompanying video (below) shows the Japanese keyboard functions of the upcoming iPhone 2.0 firmware.

According to the post users will be able to choose between a QWERTY-keyboard and a Japanese mobile phone style keyboard and from there can select either a multi-tap style kana keyboard or a sliding keyboard.

The post explains, “Japanese kana letters are organized in groups of five according to a beginning letter and corresponding vowels (a i u e o), so you can either put in the first letter and then hit the same key between 1-5 times to get the right sound (multi-tap), or you can put the first letter in and then tap and slide through to see all five sounds and pick the right one.”

Video after jump.