Merely a perfect copy of the original Ryōko Yakushiji based on her DNA after failing Hangon and modern cloning procedures twice, she was being used by Ruriko as a means of taking control of JACES from the entire Yakushiji family. Over time, Monami decides to join with Ryōko due to her feelings for Junichiro. Her name, originally means "My friend" in (French: mon ami), is given by Ryōko when Junichiro misunderstands Marianne and Lucienne's pronunciation. She is known to the JPP as R-9.
(Source: Taro Iwasaki (2008-09-06). "Linen Trap" (in Japanese).)