shibuyabashi – A place name. “Shibuya” (famous district in Tokyo) + “bashi” (bridge). Could be a venue, event, or a producer alias.
rar – A compressed file format, common in piracy scenes. better – A subjective claim in the original search, probably meaning “this rip/release is better quality than other versions.”
It’s impossible to write a legitimate, informative “long article” about the keyword you provided because that specific string of text— "051230lost raritiessoul foundation dvdeditionshibuyabashic69rar better" —is a real product, album, or official release.
c69 – Likely refers to (Comic Market in Tokyo, Dec 2005). C69 is a major doujin (self-published) event where indie music, games, and art are sold.