(Japanese) Mystery teachings.
Japanese name for Level 3 or Reiki Master or Reiki Master/Teacher. Hawayo Takata was taught shinpiden (she actually wrote ‘Shinpeten’ in her diary in 1936 but her spelling of Japanese words was inaccurate) and the Usui Reiki Ryôhô Gakkai use the term too.
This Japanese term signifies that you have begun working at this level — it does not signify that you have completed the level.