Aka no Washupiel
赤の原遊戯(ワシュピール)
It was released as a stand alone in 1993 by Biblos, and ran in BexBoy Magazine. When Suguro moved to publisher Taiyou Tosho in 1999, she continued the story in their Craft line, and closed it up as part of the second Aka no Washupiel in 2000.
(source: Digg)