Kyokujitsu Isshin-ryuu

The Kyokujitsu Isshin-ryuu is a style of swordsmanship passed down in the Kurogane Household.

Description
The Kyokujitsu Isshin-ryuu is a swordsmanship taught in the Kurogane Household since the era of samurai and taught to several children in the household. Though due to him being born as an F-Rank, Ikki was never able to join the other children in their training sessions, however, Ikki learned a number of techniques after watching the training session and seeing his elder brother, Ouma Kurogane who was training by himself even when everyone else left even the teachers left.

Techniques

 * Kyokujitsu Isshin-ryuu - Karai: This is a technique, in which the user performs a diagonal slash with one hand, then it is followed by a strong punch with the other.
 * Kyokujitsu Isshin-ryuu · Jin no Kiwami - Amaterasu: A secret technique, where the user utilizes all their muscles to deliver a fast strike at godspeed.
 * Kyokujitsu Isshin-ryuu · Retsu no Kiwami - Amatsukaze: A secret technique taught in the Kurogane Household for several generations, where the user performs a continuous series of one-hundred and eight slashes, which overpower the opponent with strength and speed.

Users

 * Ouma Kurogane
 * Ryoma Kurogane (Possible)
 * Ikki Kurogane (Blade Steal)

Trivia

 * Due to no one in the Kurogane Family not wanting to teach him anything, Ikki stole glances from the training sessions of the other children. However, he was able to learn a number of techniques (if not all of them) via watching Ouma train on his own even when everyone left.
 * Kyokujitsu references to the flag used in Japan for Ground Self-Defense Force.