B. ICHI is a manga by Atsushi Ohkubo, of Soul Eater fame. In B. ICHI, there are a certain group of people who are able to tap into a large percent of their brain power, resulting in powerful abilities. These people are called "dokeshi", and they are granted these powers at the price of one condition, which is different for each dokeshi. For the main character, Shotaro, that condition is no pain at all. he is simply required to do one good deed a day. The ability that he is granted from this is to gain the attributes of an animal by chewing on its bones. For example, if he chews on a bird's bone, he can fly.
When Mana meets Shotaro on her travels, she expects nothing but trouble from Shotaro. Much to her surprise, he takes off into the sky like a bird. While Mana may find the power amazing, the characters live in a world where dokeshi are frowned upon. When the governor goes missing, all dokeshi are immediately put under suspicion. The optomistic Shotaro, however, refuses to be discouraged and chooses to journey with Mana.