The three types of hoyo, hyakkanichi, isshuki (the first anniversary of one's death), and sankaiki (second anniversary of one's death), were added by the influence of religious services of Chinese Confucianism.
この「百ヶ日」と「一周忌」、「三回忌」の3つの法要は、中国の儒教の祭祀の影響によって付加されたものである。