Fun Facts regarding "U" (1/30 - 1/31/13):

* This is the opening theme for the brand-new beat-em-up visual
  novel "Material Brave Ignition."

* That makes this one of Kotoko's newest songs as of the time
  of this writing.

* Added for 2018 Definitive Edition: The girl with the black
  hair you constantly see in the OP is Ena Kuraki.  She's the
  energetic type who just jumps all over the protagonist with
  great affection up-front, proclaiming herself to be his
  childhood friend (though he himself doesn't remember).

* The Hard chart was designed to be fun, with some crossovers
  peppered about here and there and some candle steps for Kotoko's
  sudden pitch changes.

* The Expert chart has more crossovers, and some bracket
  stomps near the beginning and end of the song.

* Medium features difficulty only the form of placing two
  consecutive 8th notes in lots of places as appropriate, plus
  most of the same rolls that come with Hard.

* Easy is a 5 that has lots of blue notes.  If you're good with
  rhythm, this should be pretty easy to keep up with.

* Novice is a no-frills chart.