well, his collection of minifigs is surely near complete, all the minifigs he categoriezed in his site are his own collection, and he said he is missing a few figs, maybe 5 or so.
Maybe there are a few peoples have collection like that, but not as complete i guess. To collect all the minifgs is not really that impossible, but to collect all the sets is far more unachievable.
Lastly, his site is in Chinese language, not Japanese, and this man is a collector from Hong Kong, hence the chinse site. http://www.legofigs.com/webpage/fameset_e.htm
You all can have a look in the forum and read some thread created by some of the members, they have some insane collection of minifigs...
http://www.minifigs.net/forum/viewthread.p...&extra=page%3D6
http://www.legofigs.com/forum/viewthread.p...&extra=page%3D3