Sozu was the Rokugani term for a water fountain used in gardens. The device was formed with a wide segment of bamboo, suspended above a flat rock at a slant, slowly filling with a trickle of water until it was full, tipping the balance and driving it down against the stone. The sozu broke the quietness of a Rokugani garden with the sound of a bamboo rocker arm hitting a rock. The sharp noise was intended to startle birds and other animals that might disturb the gardens.