Having trouble reading Japanese? Use SimpleFurigana - a fast and lightweight iPhone Application to add Ruby Characters (Furigana) to Japanese Text.
SimpleFurigana automatically annotates Chinese characters (kanji) in Japanese text with hiragana or romaji (latin characters). Both vertical (tategaki) and horizontal (yokogaki) layouts are supported. Annotated text can be printed or shared. No network connection is required for annotation.
Use the furigana app extension to add furigana to selected text in Safari as well as many other apps. You can even add furigana to entire webpages to help you navigate the web in Japanese.