|Appearances||Forbidden Siren 2|
|Voice Actor||Mai Takahashi|
Her real name is Ryuko Kifune (木船 柳子 Kifune Ryūko?). She is the child of Noriko Kifune—the sole survivor of the Bright Win disaster that occurred 19 years ago—and Ichiro Nakajima, and is an unawakened dove due to the essence of Offshoot B entering the fetuses in Noriko's womb. Due to home circumstances, she has nurtured apart from her identical twin sister Ikuko Kifune, but initially, they shared the same face.
A year prior, the monster's essence awoke and her face changed (to that of Kanae and Yuri), and under the control of the dove's personality Ryuko ran away from home. Ryuko, living as another person in Tokyo while afraid of the things happening to her body, later meets Soji Abe, and they move in together. Tagawa is the surname of the owner of the restaurant at which she works. Although she tries to live as a human, she attracts the ire of Mother and is killed by Yuri Kishida.