VERY interesting, I will check out these songs for sure! But the list is not eligible I'm afraid, since it's not a top 100 from combined staff but top 5 lists from 20 different Japanese celebrities.
Well, it seems that this is the only list of japanese songs so far...
There is some good stuff here, I checked a few songs and I liked some. But others, like the ones selected by Fumika Hideshima, are pretty bad IMO.