The Japanese language is written with a combination of Chinese characters called kanji and modified Chinese characters called hiragana and katakana. The system used to input Japanese on mobile phones is based on the numerical keypad. Each number is associated with a particular sequence of kana and, in one embodiment, a button is pressed repeatedly to get the correct kana, while the number of presses determines the row. Marks, punctuation, and other symbols can be added by other buttons in the same way. Kana to kanji conversion is done via other keys
After the kana have been input, they are either left as they are, or converted into kanji (Chinese characters). Various techniques have been implemented by mobile phone developers to enable Japanese language input on mobile phones. In touch sensitive phones, Japanese language keyboards provide 12 keys of kanji characters, the selection of one character of which highlights the character as well as four alternatives to the main character which a user can select by sliding their finger from the selected main character to the alternative character. A sub-menu is then presented in the text entry area with additional options.