This is a music video for a song from angela’s 3rd major-label LP, from 2006. The song is an “image song” related to a 51-minute-long “TV special” which is a prequel to the 2005 mecha anime series Fafner in the Azure: Dead Aggressor.

(For more information about the song, see this page on one of Wikia/Fandom.com’s wikis, but be warned that — as is generally the case with that particular wikifarm — this website tends to have so many obnoxious autoplaying videos & other extraneous bloat that opening any page hosted there might slow your computer/browser down to a crawl!)