Nataku is a man-made perfect human, a result of bioengineering. "A human
born without the need of a woman's body". It does not know emotion, and
is a sexless living organism, just like an angel. Its name "Nataku" is
from ancient Chinese mythologies, in which there was an emotionless god
named "Nataku" who has no soul.
Nataku is created from a human girl, who died from a disease. The girl's
grandfather, as a biochemical engineer, recreated her in hopes that he
can bring her back to life. Nataku is resulted but it only has very vague
memories that belong to the girl - memories of the person that she loved
the most - her father.