Lyrics to Fuwa☆Fuwa Time by the anime girls of K-ON! It's a pretty fun song, but the three minute version kind of sucks versus the one used in the anime.
http://honya-ch.com/2009/05/17/lyrics-k-on-insert-song-fuwa-fuwa-time-by-sakurakou-k-on-bu/
http://honya-ch.com/2009/05/17/lyrics-k-on-insert-song-fuwa-fuwa-time-by-sakurakou-k-on-bu/