This study aims to realize clothing with a psychological function that enhances self-esteem and reduces loneliness and anxiety. To reduce loneliness, we propose expressing another self in active costumes with dynamic transformation. This paper first discusses the design concept “another self” and overviews fashion designs that have mimicked heart and lung activities. Next, we detail our own design and implementation of dynamically transforming active costumes. This paper describes the implementation of hardware and software features into clothing, including expanding and contracting ellipsoidal sleeves and an inflatable and deflatable torusshaped skirt. A rack and pinion mechanism driven by computer-controlled motors dynamically transforms the ellipsoidal sleeves. The pneumatic actuator comprised of three-layered chambers and computer-controlled electric fans dynamically transform the torus-shaped skirt. (Misako Ando, Sakiho Kai, Chiaki Ujihira, Keiko Miyatake, Takao Furukawa, Kaoru Mori, Makoto Hasegawa)