The eldest of the sisters is Noyamano Rika who is the former Thorn Queen of the Sonia Road who once killed a bear with her bare hands, Sora Takeuchi's lover and is currently in a machine designed to brainwash her at a certain time. She is a former member of the original Sleeping Forest and like every original member she has a virtual representation in the Inorganic net. She is currently pregnant, the baby's father being Sora. She makes money from being a pro-wrestler and has taken care of Ikki and all of her sisters from a young age and is not related to any of them.
The second oldest sister is Noyamano Mikan who has a love of retro games and is a believer in corporal punishment. As such, she regularly beats Ikki and is responsible for giving him his current tolerance of injury. She is a current member of Sleeping Forest.
The second youngest is Noyamano Ringo. She has feelings for Ikki but doesn't confess to him (but has, however, kissed him) because her duties as leader of Sleeping Forest require her to treat him as an enemy. She helps Kogarasumaru out in times of crisis under the guise of Croissant Mask, although Agito Wanijima and Simca know her identity. She is currently torn between her feelings for Ikki and her duty as the leader of Sleeping Forest. She also competes with Simca and Kururu Sumeragi for Ikki's affection and is the natural enemy of Simca.
The youngest sister is Noyamano "Ume" Shiraume. Ume frequently toys with mechanics to create robots that resemble gorgons. She is the weakest member of Sleeping Forest, but is a skilled fighter in a zero gravity environment. She is frequently bullied by Ikki at home, and is an active Sleeping Forest member. She has the same amount of skill as Kururu Sumeragi.