Tensei Contract Seal

This dangerous sealing technique allows a member of the Tensei clan to strip their opponent of their chakra. To do this, they first must make physical contact with their target, placing the seal on them. Then, when the target next uses it's chakra, not only does it fail, it turns the chakra used into chains of chakra that then connect to the user's body. These chakra chains are intangible and non-removable by normal means. After this, the chakra of the target is drained out totally and sealed within the user's body.

Koga explains that there is a way to undo this technique before the chakra of the target is drained (because after the target is drained, it is irreversible), but it involves the target having to have knowledge of the technique itself and knowing the reverse technique.