At 28 years old, Nanase is the eldest sister, who works as a data processor in an office. Her power is the Earth Dance of Flowers, the ability to summon a whirlwind of flowers, to absolutely no effect. There are many hints that she would like to be a transsexual. Her name is derived from nana, the Japanese word for "seven" (for which another word is "shichi"), thus she is the 7th of the Sisters.
from wikipedia