Adamantine Sealing Chains

The Adamantine Sealing Chains is a fūinjutsu used by members of the Uzumaki clan.

Usage
This technique moulds the user's chakra into chains which, after materialising, can be used for various purposes such as physically restraining or directly combating targets. When used offensively, the chains are strong enough to damage Wood Release techniques as strong as the Wood Release: Several Thousand Hands.

When using this in conjunction with her "special chakra", Kushina was able to restrain Kurama in Naruto Uzumaki's mind. These chains also made up her seal, completely pinning the fox down with several spikes in her own mind. Even while near death, Kushina was able to use these chains in the physical realm to restrain Kurama, enabling Minato Namikaze to use the Dead Demon Consuming Seal. This involved five chains emerging from her back and burrowing into the ground, after which they would surface and criss-cross multiple times over the target, holding them down.

Variants
Using her chains, Kushina could also erect a barrier strong enough to prevent anyone or anything from entering or leaving the perimeter defined by the chains. The barrier was very durable, as Hiruzen Sarutobi stated that there was nothing anyone could do to interfere with what Minato and Kushina were doing once it had been erected.