Reinforcement

Reinforcement (強化, kyouka) is an advanced hiden ninjutsu ability developed by Koyoichi with the purpose of pushing a basis to the utmost. It is the foundation of shape manipulation that enhances the existence of the target by applying chakra, but as no clear expression of how much it can be enhanced is defined, almighty reinforcements are rare. It is the same as adding something to an object that is already complete, in case of failure the target will receive it as a poison. Success requires a good grasp of the inner structure to fill openings with chakra. Reinforcing the purpose of existence would be increasing the sharpness of a knife, the nourishment of food, or in the case of a living creature, physical strength and durability. It is impossible to reinforce something vague. As living things will resist invasion of your chakra, reinforcing someone else is the hardest. By putting this in application, Koyoichi is able to create a bow out of the branch of a tree, repair a leather ball, or change the shape of an object.