It is said that Prince Shotoku on his sickbed ordered Prince Tamura (later Emperor Jomei) who came to visit him to promote Kumagori-shoja Monastery to a full-scale temple.
病床にあった聖徳太子は、見舞いに来た田村皇子（のちの舒明天皇）に、熊凝精舎を本格的な寺院にすべきことを告げたという。