Circle, Triangle, Square is a minimalist design created by Tokyo-based designer id inc. The project is a series of graphically shaped leather accessory cases. Each shape casually shows its function. “Circle coin case,” to keep the round shape without using any clasps, this structure can be opened by pushing both edges. “Triangle key case,” when opening it, it becomes a shape like a triangular pyramid. This steric shape makes it easier to take stuff out. “Square card case,” with a minimum of turnback and slash, bills, and cards can be stored.