[日本語がまだありません。書く暇が出来たら書きます。^^;] I've always felt the same about Japanese manuals that come with products over here.
Theres just too much info in them - I only end up reading the quick start manuals and the rest just sits there until I find time to look for the PDF version online so that I can throw the paper version away.
In case you are wondering - I rarely sell my unwanted gadgets and always end up giving them away so never bother to keep the manuals.