Yu is about having courage but it is not just mere bravery. It is about doing what is right, when it is right to do so. Any warrior can run into the thick of battle and be slain. The Samurai termed this a ‘dog’s death’ and not true bravery.
True bravery comes about by having deep insight into non-duality and being open. This is the spinning of the Ajna Chakra. Often called the Third Eye, it is considered the sight of deep spiritual insight. It is here we see deeply into our truest nature, freeing us from the shackles of our deepest fears. When all fear has been removed, courage tinged with bravery has a chance to grow. This is what many Samurai were looking for....the removal of fear and the growth of bravery, heroism, courage.
Ajna Chakra is also considered the sight of our psychic nature and insight into the wonders of the universe. This Chakra is very white. I had an experience with it many years ago during zazen. I had been sitting for about 30 minutes and one of my legs had fallen asleep. When I switched my leg positions, a white-laser beam of light shot in between my eyebrows almost knocking me over backwards off my zafu! It was strong and left a deep impression on me. I'll never forget the intensity of that light.
A simple candle meditation can help simulate and stimulate this chakra and the quality of bravery. Sit in a meditative posture with a lit candle in front of you. Gaze at the candle for a few minutes. Then close and cover your eyes with your hands and just allow the after image sit in your vision. Notice how when you try to 'see' the flame, it will move...just relax and allow it to be it will be there. This allowing opens your nature 'to be', which requires bravery of a kind you have to practice. It is openess that can feel vulnerable as well. Too often we strain to see...it takes courage to see without seeing, by letting go. Sounds weird, but try it. You'll discover the quality of Yu.
Many blessings.
Hands palm to palm,
Shinzen