The Prince Regent Shōtoku Taishi (574-622) was a skilled statesman and an early supporter of Buddhism. He attracted many legends; it was said that he could speak at birth, that he recited mantras (Buddhist prayers) as a child and performed acts of piety. He was worshipped as an emanation of the bodhisattva Kannon (Sanskrit: Avalokiteshvara). He is variously represented - as a child, as a young adult (praying for his father's recovery) and as the adult Prince.
This is known as a Namu Butsu ('Hail to the Buddha') representation, as a child reciting mantras. It has been popular since the Kamakura period (1185-1333). This imitates thirteenth-century examples.