Yin Seal: Release

After focusing and storing an amount of chakra over a period of time in the Strength of a Hundred Seal on the user's forehead, the user can release any amount of chakra with this technique by dispersing the seal and pumping the stored chakra back into the user's body. Thanks to the released chakra from the seal, Tsunade is able to use unique techniques. Firstly shown, she has used this stored chakra to perform the Creation Rebirth technique on herself and later on a separate occasion healed a vast amount of people through Katsuyu. During the Fourth Shinobi World War, Tsunade is also able to use the Ninja Art Creation Rebirth — Strength of a Hundred Technique after releasing the seal. The user can even channel the released chakra into another person by extending their markings onto them through physical contact, as demonstrated by Sakura.

Trivia

 * After using the chakra from the Strength of a Hundred Seal, if there is any leftover chakra, Tsunade and Sakura may use it to re-form the seal.
 * The size and form of the release markings may depend on how much chakra is being released from the seal, as Sakura and Tsunade's seals had only spread around a small area.