大姫・乙姫考

──中世の姉と妹、それぞれの役割と人生──

抄録

It was customary in Japan from the Heian period on to use names for children that expressed the birth order of the siblings. Thus male children were called Taro (for the eldest) and Jiro (for a second son), and daughters were given names like Ohime (for the eldest daughter) and Otohime (for the second daughter). This essay will consider the significance of using such birth-order names for daughters, in spite of the fact that in principle inheritance went only to sons. This examination will clarify the roles of daughters in the medieval family, and changes that occurred over time. Finally I will consider the images that are attached to these names—Taro, Jiro, Ohime and Otohime.
In the Heian and the Kamakura periods, Ohime was used for a legitimate daughter who was expected to live to serve her father's family, and sometimes this would in fact involve great sacrifice. This is the picture of "Ohime's" life as described by Baba Akiko. On the other hand, this daughter also exercised authority in the family, and as the beloved daughter of the father she would receive property as inheritance. In this kind of family, the younger daughter Otohime was simply seen as "a spare" in case something happened to her elder sister.
This practice of using birth-order names disappeared toward the end of the Kamakura period. Along with the disappearance of the name, the authority that the elder sister had exercised was taken over by the eldest son. This was the beginning of an era in which "legitimate daughters" were no longer present.
The "Oto" character, which has been used for a name for a younger sister, came to be applied to young women regardless of birth order. However, in the stories from this period, the "Otohime" have no obligations to their father's families. In the latter part of the medieval period, women who were driven out of their own families at the time of marriage, were all a kind of "younger daughter."
In stories from this period, the love object of Otohime is Taro, the eldest son. However, it is important to note that this "Otohime" does not refer to a younger daughter.
This essay thus looks at the shift from the "Age of Ohime" to the age of "Otohime"—or to the age in which Taro, the eldest son, becomes more powerful.