the average american probably doesn't know any famous japanese people. there certainly ARE japanese who are famous here, but nobody is at a level of popularity where everybody in america knows who they are. ichiro suzuki was pretty big when he first came here but even he didn't get to that point. they showed takeshi's castle on TV here, but they gave it a parody dub. poor beat became "captain tenille". anime fans in the US know him because of battle royale.

this site, however, is (obviously) populated by westerners who do follow japanese pop culture. this is really uncommon in the states to begin with. most of us got into it from japanese animation and manga (which are just barely below the mainstream). if you ask us about this stuff, we're much more likely to know. the average american won't know puffy. kids probably would, but they would know them as cartoon characters, not a band.