Bowing is a deeply ingrained custom in Japanese culture and done on a daily basis. There are many varieties of bowing, from sitting (seiza) to standing (seiritsu).
Depending on the occasion, the angle of your bow increases from about a 15-degree bow for greeting to a 30 to 45-degree respect bow.
It is worth noting that when bowing, the slope of your back and the back of your head need to form a straight line. A curved bow is considered impolite.
SOURCE: www . tofugu . com/japan/bowing-in-japan/
