Installing "Lets Japan No5" will enable Japanese (including enable the wlncs, change font to support Japanese and support various of IME for Japanese) on your X51V. After that you should be able to use ebpocket ( from http://ebstudio.info/download/ebpocket/ebppc128_free.zip) and display/enter Japanese.
多谢楼上的回帖,潜水数日已解决。after updating to A04,
first download echinano5,then setup in my dell x51v , i can use ebpocket1.28 free version,
second i setup compobox vga and dict, last setup dbmjd