This is a music video done by CLAMP that features a bunch of their characters including those from xxxHolic, Tsubasa, Cardcaptor Sakura, Magic Knights Rayearth, Kobato, Chobits, Clover, Wish, Angelic Layer, X, and others. The plot, if you can even call it that, is the two Mokonas running around the different dimensions, running into all the characters. The animation is beautiful and the music is catchy, so it's a nice watch. A nice improvement over the first music video.
It is just a music video, so it's a bit hard to rate it. CLAMP fans will enjoy it much more than non-CLAMP fans for sure; I'm a CLAMP fan, so I'm rating it as one. As a music video, I find it pretty good, although not as great as some music videos with a plot.