The theme for the sixth (not first, ignore the video) boss in END ROLL. Simple, yet effective.
Artist: Segawa (Implied by the Readme)
Game: END ROLL
Wanna play the game? - http://www.vgperson.com/games/endroll.htm (English Translation)
I don't own this song, this game, or any of this content. All rights belong to their respective owners. Protected under fair use.