Protocadherins (Pcdhs) have multiple clusters, which have been proposed to contribute to produce sophisticated neural networks for higher brain functions. Pcdh-α has twelve clusters (α1-12), and cPcdh-α1,12 mice have only α1 and α12 but not α2-11. However, no apparent abnormality has been found in cPcdh-α1,12 mice, so far. To investigate the roles of clustered structure of cPcdh-α in higher brain function, we investigated visual short-term memory in cPcdh-α1,12 mice. First, we tested visual short-term memory of spatial information using a T-maze task. In the control visually-guided task, wild-type and cPcdh-α1,12 mice were trained to choose the branch marked with a white panel to obtain a small amount of water. Both types of mice successfully learned the visually-guided task. In the memory-guided task after the control task, mice learned to select the branch based on the short-term memory of a white panel presented at the starting area. In this memory-guided task, the performance of cPcdh-α1,12 mice was significantly worse than that of wild-type mice. We further tested visual short-term memory of shape information using an M-shaped maze equipped with a computer display. In the control visually-guided task, the cue shape (A) or (B) was presented at the center of the display, and the shape (A) and (B) were presented at the left and right branches immediately after the cue period. Mice learned to choose the branch marked with the shape different from the cue shape. Both types of mice successfully learned the visually-guided task. In the memory-guided task, the delay period of 20 s was set before the shape (A) and shape (B) were presented at the left and right branches. In this memory-guided task, the performance of cPcdh-α1,12 mice was significantly worse than that of wild-type mice. These results suggest that multiple clusters of Pcdh-α are required for producing sophisticated neural networks, which play essential roles in short-term memory of visual space/shape information.