Ango (intensified practice of Zen Buddhism) (安居)
Ango is an ascetic practice conducted for a specified period at one place by a group of Buddhist monks who have been engaged in separate activities. Ango also refers to the period of the ascetic practice.
It is believed that one's horo (career as a monk) is promoted by one rank by participating in a geango (ango in summer).
Ango in the context of Buddhism
Ango was originally a Sanskrit expression meaning the rainy season, which was translated into Japanese.
Ango originally meant to abstain from going out (outdoor ascetic practice) and stay in a place in the rainy season to prevent futile destruction of life, because plants grow rapidly and many small creatures, such as insects and snakes, become active in the rainy season. Because ango takes place during the summer having the rainy season, it came to be called geango (summer ango), or uango (rain ango).
It is said to have started during the era when Shakyamuni was alive, and to have been introduced to China and Japan along with Buddhism. Ango came to be conducted not only in summer, but also in winter (toango), and the number of conducted ango was counted towards one's career in the Buddhism world, giving it much significance and making it a criterion for future promotion.
Even today, ascetic Zen monks conduct ango and undergo a hard ascetic practice, staying in the temple's precinct from Kessei, which is the start of ango, until gege, which is the end of ango.
Ango in social context
Also, the article on the Emperor Temmu in 683 depicts episodes of a plurality of ango conducted in the imperial court.