Sai

is a Kidō spell.

Description
This is a restraining spell that contains the limbs to immobilize the enemy. The practitioner points using his/her index and middle fingers at the intended target(s), causing the target's arms to lock behind their back. The spell is usable on a single target or a significantly large group of people.

Incantation
Unknown.

Known Practitioners

 * Rukia Kuchiki
 * Renji Abarai
 * Fujimaru Kudō