Within the palace of the Empress Saimei regnant, in 612 a naturalized citizen from Kudara (one of the three nations in ancient Korea) built a Shumisen and Kure-hashi Bridge on Isonokami no ike (a pond in Isonokami) located south of the Imperial Palace.
斉明天皇の宮では、612年百済の帰化人が皇居南庭石上の池畔に須弥山と呉橋を築いたとされる。