Hardly the strangest thing I've seen all day. Maybe it's just that for awhile a friend of mine who was teaching English in Japan would regularly send me links to Japanese music videos, but I'm kind of inured to this kind of thing.
That said, I doubt that they have much of a chance of catching on in a big way in the US. But you never know with pop music. I wouldn't say that it's anything to do with the video itself (I don't really think it's any better or worse than a lot of American music videos), it's just hard for a foreign language group to break through, even with an English language single.
Not my thing, but I'll wish them the best of luck anyway. If nothing else their video seemed to be tongue-in-cheek, so I'll give them more leeway I would have if it had been achingly sincere.