Hasshoken

Hasshoken is a martial art used by the Chinjao Family.

Description
As stated by Gatz, this fighting style allows the user to control vibrations around their limbs — whether it be fists, legs, or elbows — to generate shock. This shock is powerful enough to destroy a metal shield or defeat a strong man easily. Sai also claimed that these attacks are unblockable and reverberating, causing defenses to shatter.

This fighting style is only used by Chinjao Family which are also members of the Happo Navy, and may thus be a secret family or special army technique.

Trivia

 * The ability to generate and control vibrations is similar to the Gura Gura no Mi.