She was adopted into the Iga clan by Akame many years ago, during the war against the Koga clan.
Ginga Densetsu Weed: Orion
She left the Iga clan when she was older and settled into a human household with an unknown mate. When Shirozaru, Rara and Muu was born, she made him promise her not to look into Akame or the Iga Clan, to which he protested. When he was older, he left with his two brothers to find Akame.