Wearable robots for use in the human environment must be inherently safe, compact, lightweight, and efficient at the same time. Conventional wearables developed in the past are generally composed of bulky rigid frames, which cannot guarantee the inherent safety of the users. To address this issue, soft wearable robots have been proposed as a solution for safe and lightweight wearable robots. However, due to problems such as force transmission, durability, and limited space, soft wearable robots capable of assisting the users with sufficient performance, are not commercially available. In order to develop soft wearable robots for commercial use, we are conducting research related to 1) designing a novel concept high-spec pneumatic actuator, 2) developing of flexible force transmission structure capable of effective force transmission, and 3) improving the overall efficiency of the pneumatic system by novel recirculation mechanism. By actively conducting these researches, we aim to develop a highly effective soft wearable suit for human assistance and rehabilitation without degrading the user's comfort.