I would say she definitely is not a junior idol since of the two DVDs she has done, both are rated R-18. The DVD at auction is NEWDR-002, release date 2012/10/30. Info here:
https://www.suruga-ya.jp/product/detail/139031740
Her other DVD is DRST-002, release date 2011/12/20. Info here:
https://www.suruga-ya.jp/product/detail/139028646
This is a more complete cover of DRST-002:
I could not find anything on AO about these. I have found other sites that purport to have DRST-002 for download. The clues to finding these were given at an auction for the same DVD where the seller gave a partial scan of the back, found here:
https://page.auctions.yahoo.co.jp/jp/auction/h443706471
As granatnik has said, this is a really obscure DVD. At least the seller has characterized this as "very rare," 激レア. (and thanks to granatnik for the reply on another post and the great covers.)
The back cover shows both DVD codes. I can only guess that NEWDR-002 is an "outtake" video of DRST-002, but I'm probably wrong. The covers of both seem to show similar scenes, in particular, one where she is wearing purple panties and clutching an orange strap. Hovering Google translate over the cover really didn't give me a lot more info.
I really didn't answer Stooky Bill's question, Who is “大島あいを?”, but I hope I have helped.
