Ju-Shin, or “gentle spirit” is a formalized exercise combining a sequence of jujitsu techniques against an imaginary attacker in which one technique leads into another without “losing” control of your imaginary attacker. The goal is to develop a sequence of 5-10 techniques or movements into a relaxing exercise that improves one’s balance, body flexibility, memory [the development of mushin], meditation skills, and the efficient management of your ki [or energy-flow].