The Infinite One-Sword Style (無限一刀流, Mugen Ittōryū) is Mifune's sword fighting style. It is also known as Infinite Sword Attack in the English dub.
|“||The swords may only be stuck in the ground, but they all radiate danger.||”|
—Black☆Star, Episode 28
Mifune's Infinite One-Sword Style is a fairly unique style of sword fighting. Rather than relying on a single good quality blade Mifune makes use of hundreds of katanas scattered around the battlefield. Mifune does not care about the quality of the blades he uses, and uses a variety of moves making use of a single blade, or even multiple blades at the same time.
Because of his reliance on hundreds of blades scattered around the battlefield Mifune almost always has a blade, or multiple blades handy for use. He uses his swords for various purposes beyond normal melee attacking, including use as projectiles, paths to walk on, pins to hinder his opponent's movements, and also use for making multiple simultaneous attacks on an enemy.
Before a battle, Mifune declares the use of his Infinite One-Sword Style and throws his case of swords up into the air releasing a shower of blades which scatter themselves all over the battlefield in nearly every spot one can see. Often the shower of swords is also accompanied by long winding yellow tape with 'KEEP OUT' written in English all over it which winds itself around the entire battlefield enclosing it. Black☆Star has noted an oppressive feeling coming from each of the swords stuck in the ground.
Mifune only uses his Infinite One-Sword Style against powerful opponents, as other opponents he can easily dispatch without engaging in his fighting style. He uses his Infinite One-Sword Style in all of his fights against Black☆Star.