|Steel Release: Impervious Armour|
|Movie||Naruto Shippūden the Movie: The Will of Fire|
|Appears in||Movie only|
|Classification||Kekkei Genkai, Ninjutsu, Chakra Flow|
This technique allows the user to turn their body into black steel, making that part invulnerable. Hiruko states that blades do not affect him at all due to this ability. The portion converted into black steel is similar in appearance to Kakuzu's Earth Spear technique. Hiruko uses it to counter Sai's tantō, causing it to snap clean in half on impact.