How come PSP is only console which actually owns Ds and Wii at Japan?

[Kasz216]

Cause DS has sold over twice as much.

I Expect PSP to still fall short of DS by quite a bit in japan.

As for Wii? I'd guess PSPs multimedia functions. Since the Wii is still selling more software by a bit.

That and handhelds just seem more popular in japan then everywhere else.