Agata no Inukai no Hirotoji (県犬養広刀自)
Background of Hirotoji
She originated from Agata no Inukai no Muraji Sukune (third highest of the eight hereditary titles). Her father was Agata no Inukai no Morokoshi. Her mother was unknown. Among the members of the family, there was Agata no INUKAI no Michiyo, the wife of FUJIWARA no Fuhito.
Hirotoji, the wife of Emperor Shomu, had one son and two daughters: Prince Asaka, Princess Inoe and Princess Fuwa. Emperor Shomu had Empress Komyo as second wife with whom they had Prince Motoi and Princess Abe (later, ascended to the throne as Empress Koken). Since Prince Motoi died within a year after his birth, Hirotoji was the only person to give birth to a hopeful son of Emperor Shomu.
It is not certain when Hirotoji became a wife of Emperor Shomu, but according to the "Shoku Nihongi" (Chronicle of Japan Continued), Prince Asaka was 17 years old in 744. From the above, it is known that she became a wife of Emperor Shomu as early as 728. According to one theory, she became a wife of Emperor Shomu earlier than Empress Komyo did.
Roles of Hirotoji
The background of Hirotoji's marriage with Emperor Shomu closely related to the existence of the Michiyo. Perhaps, it can be understood that she became a wife under the recommendation of Fuhito and Michiyo. Princess Inoe, the daughter of Hirotoji was selected as Saio (Imperial Princess appointed to serve the deities of the Kamo-jinja Shrines) and Prince Motoi, the son of Empress Komyo, was installed as the Crown Prince soon after his birth. Because of that, it was possibly planned from the beginning that Hirotoji was expected to have a Princess and Empress Komyo (Mother of Empress Komyo was Agata no INUKAI no Michiyo) was expected to have a Prince so that their children could become the Saio and the Emperor.
Furthermore, Princess Inoe (the daughter of Hirotoji), Princess Sakahito (the daughter of Princess Inoe and Emperor Konin) and Princess Asahara (the daughter of Princess Sakahito and Emperor Kanmu) were selected as Saio for three generations.
In view of the above, there was a theory that Hirotoji or Agata no Inukai family was expected to play a role in the so-called 'Womb of Saio.'
As already mentioned, Prince Motoi (the child of Emperor Shomu and Empress Komyo) died at an early age, so Prince Asaka was expected to be the Crown Prince. To prevent that, the Fujiwara clan installed a Crown Princess for the first time. During that time, Prince Asaka also died at an early age (There is a theory that he was killed with poison by FUJIWARA no Nakamaro).
Then, Hirotoji died in October 762, 18 years after Prince Asaka died. She was ranked as Shosanmi (Senior Third Rank) at that time. The children that Hirotoji gave birth to all had tragic fates, especially the eldest daughter, Princess Inoe who became the Empress of the Emperor Konin, but was deprived of her title later and died from mysterious causes. Fortunately, Hirotoji did not have to face that.