This letter discusses the design for wire-driven continuum manipulators. To achieve multiple desired postures, a novel design method that analytically determines the mechanism and control parameters of the manipulator is proposed. First, by introducing a discrete model of the manipulator, the governing manner of the posture for tension and wiring is formulated. Based on the governing manner, the synergy relation of wire drive systems is derived. Next, by employing the principal component analysis, the synergy relation of multiple desired postures is derived. This synergy relation is customized suitably for designing the manipulator. Then, by focusing on the isomorphism of the mathematical operation structure in the two synergy relations, an analytical determination method for the mechanism and control parameters of the manipulator is developed. Finally, the proposed method is experimentally demonstrated. A continuum manipulator with two wire drive systems is developed for attaining five desired postures. The validity of the proposed method is confirmed through the design and fabrication of the manipulator and the attainment of desired postures.