you can effectively ignore the drm since you're not going to be reading Japanese language books are you?
I use the librie for reading converted text files, pdfs and jpg'd comic books
all of which i've converted myself (it's easy to do so) but you can download direct to librie format from manybooks.net
this tool looks good (if you convert a pdf to txt it'll be more readable not mention searchable and zoomable)
http://www.thebeatlesforever.com/pro...xt/abctxt.html