considering how forward-thinking and technologically savvy japan tends to be, the conspicuous lack of a sizable electronic music scene is a little baffling.. but nevertheless i really don't have much to offer in the way of recommendations. most of the japanese stuff i dig is older (like ymo) and fairly bizarre, though there's a few exceptions. i enjoy Yukihiro Takahashi's last few albums, most notably "The Dearest Fool" and "A Ray of Hope". his most recent one is more along the lines of the sketch show stuff, with perhaps a bit more of his pop sensibility. his mini-album with Steve Jansen (david sylvian's brother) is pretty solid, simply called "pulse". as far as older stuff, i love Ippu-Do's "Night Mirage", which is kind of similar to Sylvian's early 80s band's output (the band was actually called "Japan"), i.e., "Tin Drum". ippu-do's leader went on to do some interesting stuff, i like his "mod'fish" album and "forest people" is pretty good (though i actually prefer his 80s albums). Sugizo's "Truth?" album is worth checking out, though it's pretty dated sounding at this point (as is most of this stuff), but at the time it was a pretty inventive hybrid of electronica, drum & bass, jazz, and rock (he's a rock guitarist by trade). other names that come to mind are Yoshihiro Hanno (check out "liquid glass") aka multiphonic ensemble.. nobukazu takemura (who i dont personally care much for..), and Sakamoto's daughter Miu released a fairly decent electronic/pop effort in the late 90s called "dawn pink".. but really i'm probably not the best person to ask.. it's possible there's a burgeoning electronic scene there with great artists, but perhaps it's just too insular to have any exposure overseas, i really don't know at this point.
re: hiero.. man i'm at even more a loss to recommend anything new—i've pretty much been listening to older recordings and a lot of ambient artists for the last year or so. the best bet is to find a few online review-based magazines (there's a lot of them) that specialize in whatever your taste is, and just try a bunch of it until you find something. that being said, the new Junior Boys album is worth checking out "so this is goodbye". i've also played mark van hoen's latest record a lot, "the warmth inside you".. if you like singer/songwriter stuff i recommend Lori Carson's "The Finest Thing", which is a great melding of folky guitar and depressing vocals with some subtle electronic atmospheres (that description probably sounds awful, but its good!). Also Tim Bowness's "my hotel year" is good electronic pop stuff, though a lot of people dislike his vocal style. and Nine Horses - Snowbourne Sorrow is a really interesting experimental pop record that's worth checking out.