B. Ichi, Vol. 1

Most humans use only a small percentage of their brainpower, but a
certain group of people called "dokeshi" can use a greater percent of
their brain to unleash special powers, given one condition...For dokeshi
Shotaro, that condition is doing one good deed a day. In exchange, he
has the ability to use the powers of any animal by biting its bones.
When Mana meets Shotaro on her travels, she expects nothing but trouble
from the childish, ignorant boy-until he takes off into the sky like a
bird. Mana may be impressed, but dokeshi are viewed as freaks by most
of the population. And with the governor missing, all dokeshi are under
suspicion. Ever-opitimistic Shotaro refuses to be discouraged and
journeys on with Mana in the name of Justice!