I agree with Arian on the simplicity. Good use of colours, and also the outfits match with the "simple" background. This is what I call a goddamn freaking AMAZING graduation single, and PV.
EDIT: Since MM is giving me the image of a real group again, I didn't focus on one girl only. Everyone looked fantastic. I love the 80's feeling this song has, and I loved this song since the first radio rip came in. the perf. of course helped me to appreaciate it more. but still, what was the last mm pv i got really excited about..? joshi kashimashi? :0 this isn't a super high-budget pv, but the great camera angles (it's not your average H!P pv with close-ups and dance shots.. it has some more than that) and the cool outfits more than make up for it. plus, it's not sugary all sweet, actually it's as mature as Roman my dear boy. and the guitar is AWESOME.