This video showcased on the TV Commercial Blog is interesting for a number of reasons.
First of all -- it's just funny and creative.
Notice the voice. It's a baritone -- not too low --recorded very much "on mike" with just a hint of "rasp", a subtle nasality. And it sounds pretty much like a real person. That's where that subtle nasality comes in. The voice is not too pure or "sweet" --it has "character".
In Japan, a problem is that Japanese do the choosing, as far as voices are concerned. They want the effect -- the impact - the naturalness -- the intimacy -- that voices like this have -- but since English is not their native language it is difficult for them to "hear" the voices that are presented to them. And of course Japanese directors will inevitably try to get a "Japanese" sound, ending up with something purer and sweeter -- and over-pronounced, a sort of ei-kaiwa thing on steroids. Something everything is exaggerated.
You will also notice that the voice-over artist has full control of intonation and uses pitch, stress, and juncture artfully, phrasing perfectly.