The soundtrack is a song called "Particle Man" from the group They Might Be Giants; their songs aren't known for their musical prowess, but instead for their peculiar lyrics. "Particle Man" is no exception!

Particle Man has been parodied several times in the past, by Warner Brothers in particular, and as you may have guessed, was pulled into the sick and twisted world of Anime Music Videos (AMVs) in the form of a Rurouni Kenshin AMV. The idea, therefore, is not an original one, but humourous none the less.