Kachi Kachi no Mi

The Kachi Kachi no Mi is a movie only Paramecia type Devil Fruit that allows the body of the user to harden and heat up body temperature. "Kachikachi" is the Japanese onomatopoeia for stones knocking one another to create fire, a reference to the heating up power of the fruit. It can also be the sound effect of something hardening up, in reference to hardening. It was eaten by Bear King.

Strengths and Weaknesses
This fruit allows the eater to harden the body at will, increasing defense capabilities. Not even the drilling power of the King Cannon could break through it, as it was the floor caving in that killed him. The user can also increase the temperature of their hardened body portions, which can be be used to increase damage done to the opponent.

This fruit doesn't seem to have any other specific weaknesses, aside from the standard Devil Fruit weakness.

Usage
Bear King basically hardens his body to increase defense. This also augments his offense, allowing him to hit harder. He also increases his body temperature to burn his opponent on contact.


 * Hot Boiling Special (ホットボーリングスペシャル): Bear King heats his fist up and punches the enemy.

Trivia

 * The "heat-up" ability is seen once again in the anime, from the Atsu Atsu no Mi, eaten by Don Accino.