In this paper, we propose "SHAPIO"', a game controller that inputs and outputs game events through its three-dimensional shape. SHAPIO consists of multiple triangular prisms, and its three-dimensional shape can be freely changed by twisting each prism. When a game player changes the shape of SHAPIO, the game system changes the shape of an item in the game into the same shape as SHAPIO, and vice versa. The player can feel the sense of unity with the game character, because SHAPIO always has the same shape as the item. We confirmed that the shape of our prototype could go hand-in-hand with the corresponding game item in a practical response time.