However, there were several uncertainties involving the mother and father of Nagayasu, and one theory stated that Nagayasu was a foreigner (Chinese) or a descendant of Hata clan.
ただし、長安の父親や母親については不明な点が多く、一説に長安は異人（中国人）であったとも言われている。また、秦氏の子孫だったとも。