The test was a three-week period of meditation, fasting and prayer on Mt. Koriyama in Japan.  He chose his meditation site and piled twenty-one stones in front of him to mark the time, throwing away one stone at the end of each day.  On the final morning of his quest, waking before dawn, Usui saw a bright light coming toward him out of the sky.  At first he ran, but than stopped deciding to accept what was coming.  The light struck his third eye and he lost consciousness for some time.  Than he saw the symbols as if on a small screen, then he was given the information about each of them to activate the energy.
On his way down the mountain he performed & experienced 4 miracles of healing.  After returning to the monastery Usui named the Universal Life Force Energy “Reiki” and began his new life’s work.
Reiki is about your own Spiritual Growth. 
"Learn to heal thyself, Learn to assist the world."