Nature appears to us in four seasons. The spring is bright and warm, the summer lazy and hot. The fall is decked with colour with a trace of sadness, and the winter frosted and severe. Similarly, the movement of shin shin toitsu aikido are rich and varied. There is both severity and kindness, speed and calmness. It is designed to express the many moods and characteristics of men and women, young and old. But if it for one moment varies from the principles of the universe, it is no longer aikido with ki.