Masaya Miyashita is the real name of the artist using the pseudonym "SHIYAMI" or "Yasamata Shiyami". A number of years ago, this artist had been arrested for publishing doujinshi. I don't know if the regulatory troubles had resulted in the artist using multiple pseudonyms or different ones since 2008 (how annoying!). An overview of what happened is at: http://zerohiei-rgg.livejournal.com/3581.html
See the artist's archived homepages for proof of the various names he used: http://web.archive.org/web/20041208143601/http://home.e-catv.ne.jp/shiyami/index.html http://web.archive.org/web/20041209095954/http://home.e-catv.ne.jp/shiyami/dozin.htm
So, do all the different works by the artist as "shiyami" and "yasamata shiyami" get aggregated under the artist's real name of "Masaya Miyashita"? It would be quite a change for a bunch of entries.