Double Breed

is a Japanese light novel series written by Erika Nakamura, with illustrations by Fujikura Takehito. The series began publication on February 10, 2000 by ASCII Media Works under their Dengeki Bunko publishing imprint.

The series won the Gold Prize in the 6th Dengeki Novel Awards.

Synopsis
Yuki Katakura, a girl who inherits a specific genetic factor-bearing organism-commonly known as "Ayakashi", was feared to be called "white-haired head" because of her power and silver hair.

One day, while cooperating with the special forces "EAT", Yuki meets a human youth. The name of the young man is Taichiro Yamazaki. At first, Yuki was worried about Taichiro's direct words and deeds, which is a member of "EAT," but gradually he began to like his unadorned personality. On the other hand, there is one instep "mystery" who aims at Yuki Katakura. That person, Sachiko Takahashi, who made a noise in Japan as a murderer three years ago, and Yuki had a close relationship ...