OverviewPrimarily used for foundations and the like. It features an ant-shaped tenon on one side and a groove carved in the opposite direction on the other, serving as a simple joint used as a seat. Some variants have a joint pattern on the lower part of the seat.

PrecautionsWhen assembling, applying strong force can cause the male wood to break along the grain, and there's also a risk of the female wood cracking. Therefore, it's recommended to use it in places where no pulling force is exerted. The joint position should have the male wood closer to the pillar. During construction, the bottom part should be made slightly thinner.