Daijō Tennō
Daijō Tennō or Dajō Tennō (太上天皇) is a title for an Emperor of Japan who abdicates the Chrysanthemum Throne in favour of a successor. It is sometimes translated as "Emperor Emeritus".
As defined in the Taihō Code, although retired, a Daijō Tennō could still exert power. The first such example is the Empress Jitō in the 7th century. A retired emperor sometimes entered the Buddhist monastic community, becoming a cloistered emperor. During late Heian period, cloistered emperors wielded power in a system known as cloistered rule.