Noboru Takatsuki is best known as the artist behind several yaoi games for Vivid Color (link NSFW) including Silver Chaos and its sequel.
She (at least I think this person is a she) has done illustrations for several yaoi novels and drama CDs.
In addition, Takatsuki has done one manga called Renai Shinen (aka Love Is Hard) which is being scanlated by Hochuuami. It has not yet been licensed for release in the U.S.
I have a lot more artwork by this artist, so I may do another post in the future.
In the meantime, here are two semi-rare pieces of artwork from this artist.
Noboru Takatsuki's homepage