As nobody witnessed the instant when Hideyori died, and bodies had not been found, it is described in "Nihon Seikyoshi" (by Jean CRASSET) that he either died at the time of the fall of the castle or escaped accompanied by his mother and wife to the territory of a daimyo in a remote region.
秀頼たちが絶命する瞬間を目撃した者がおらず、死体も発見されなかったことから、『日本西教史』（ジャン・クラッセ著）には落城時に死亡とも母妻をともなって辺境の大名領地に落ち延びたとある。