Yukiko Takaguchi

A group of enigmatic white-haired children has been spotted at different times and places in Europe for over 500 years. Always with the appearance of 11-year-olds, they behave far more mature than they should be, never grow old, and seem to have supernatural power. What they have been seeking is a girl, and the only clue they have is a picture with a crescent moon. Now, in the year of 2012, an athletic boy named Tohma is about to be involved in this centuries-long mystery. (myanimelist.net)

Yori and his twin sister Iku used to be very close as children but lately Yori has grown colder toward Iku and is always eager to stay away from her. Iku was confused by Yori's attitude. Actually Yori is in love with Iku and that forbidden love is causing Yori sleepless nights since Yori and Iku are sharing the same room with bunk beds. Yori tried to ease his intense desire for Iku by bedding Iku's best friend. (myanimelist.net)