In novels, "mind, body, qi and spirit" usually refers to human limbs and five internal organs, mental state, qi and blood circulation and spiritual strength. "Perfect harmony" means that these aspects have completely reached the highest level, perfect and without any flaws.

This concept may come from China's ancient theory of keeping in good health, which holds that the five internal organs, qi and blood circulation and spiritual strength in the human body are interrelated. If you want to be healthy and happy, you must ensure that these aspects reach the best state.