I chose this as a post today simply because the CarTown-EX Fan Page Gift code this week was for a Shishi-odoshi. I myself had no idea what it was, so I searched it out and found a reasonable explanation that even I could understand. I couldn't help but wonder who else had no idea what this was. I hope this is helpful to someone else.
Sōzu is a type of water fountain used in Japanese gardens. It consists of a segmented tube, usually of bamboo, pivoted to one side of its balance point. At rest, its heavier end is down and resting against a rock. A trickle of water into the upper end of the tube accumulates and eventually moves the tube's centre of gravity past the pivot, causing the tube to rotate and dump out the water. The heavier end then falls back against the rock, making a sharp sound, and the cycle repeats. This noise is intended to startle any herbivores such as deer or boars which may be grazing on the plants in the garden.