The Barracks can be unlocked by building the Kirin Stone Statue. You can acquire JP from the Barracks relative to the length of time a unit has been installed there to replenish provisions. Bravery will increase, and Faith will either increase or decrease up to a certain amount.
*Some provisions provide bonus JP.
*Enhancing the Kirin Stone Statue will increase the number of units that can be installed in the Barracks.
*Visiore can be used to extend the Provisions Gauge.
*Sending units to the Barracks will have an effect on JP, Bravery, and Faith.