From the MangaHelpers website:
Siblings Ayane and Kurumi have unique supernatural powers known as Ghosts, each with their own unique rating that designates their powers. Ayane has a score of 7, while Kurumi has a score of 11. Ayane's ability allows her to control shoe laces, while Kurumi can form contracts with objects, which allow her to control them.
Ayane feels severely inferior to her sister, but will she be able to prove herself against the other Ghost-bearers in combat? [DrCoke]