Gyochu is one of the creepy germs written in Harikikigaki, a book of medical knowledge written by an unknown resident of Osaka. This tiny malevolent creature is believed to have caused human illness during the 16th century in Japan. Gyochu is a deadly critter responsible for leprosy, acts as a messenger to the underworld. On the night of Koshin-no-hi (an important date occurring every 60 days on the Chinese calendar), Gyochu leaves the body to visit Enma-daio and tell him your misdeeds. Enma-daio is known to punish people for bad behavior by reducing their remaining time on earth.