Three Arrows: The Origin of the Tradition and the 1557 Letter to Three Sons

'Three arrows' is one of the most widely known Sengoku-period instruction tales in modern Japan.

It is the story in which Mōri Motonari calls his three sons (Takamoto, Motoharu, Takakage) to his sickbed and teaches them that a single arrow can be easily broken, but three bound together cannot.

It has been repeatedly cited in textbooks, moral-instruction materials, and management books.

But when the relation of this story to historical fact is examined strictly, an interesting structure comes into view.

The 'three arrows' story, as currently known, is told in the Mōri-house origin documents, military narratives, and instruction books from the Edo period onward.

In the sources from Motonari's lifetime and the same period, the specific 'three arrows' episode does not appear.

It is an anecdote that formed in the course of being arranged as Mōri-house tradition in the Edo period and was spread on a national scale through Meiji-Taishō period moral-education textbooks.

The decisive inconsistency of the three-arrows story lies in the dates of the figures.

Motonari died in 1571. His eldest son Takamoto died of illness in 1563 at forty-one, preceding Motonari's death by eight years.

As of 1571, the second son Motoharu was forty-one, the third son Takakage thirty-nine.

The scene in which the three brothers gathered at Motonari's deathbed cannot stand, because the eldest son Takamoto was already deceased.

In modern scholarship that rigorously verifies contemporary sources, that the three-arrows scene is not historical fact has been pointed out since early on.

Does this then mean that the thought of the 'three arrows' itself is not Motonari's?

No. On November 25, 1557 (Kōji 3, the twenty-fifth of the eleventh month), Motonari issued to his three sons a letter of instruction known as the 'Sanshi Kyōkunjō' (also called the 'Three Brothers Instruction Letter,' in fourteen articles), and it survives.

The original is preserved in the Mōri house and is now held by the Mōri Museum in Hōfu City, Yamaguchi Prefecture.

Motonari was sixty-one, Takamoto thirty-five, Motoharu twenty-eight, Takakage twenty-five.

In these fourteen articles, Motonari repeatedly preaches the thought of the unity of brothers: 'The three houses of Mōri, Kikkawa, and Kobayakawa should be one body and should mutually aid one another.

The Sanshi Kyōkunjō, in fourteen articles, includes in summary the following claims.

First, the unity of the three brothers ('If the three houses of Mōri, Kikkawa, and Kobayakawa are not of one mind, the Mōri house will collapse'); second, submission to the eldest son Takamoto as the authority (Motoharu and Takakage should set up Takamoto as the main house); third, appropriate relations with retainers; fourth, gratitude to the ancestors; fifth, the recommendation of learning.

The writing is in a careful tone close to spoken language, and is a precious primary source transmitting concrete house-management guidance for the period of headship transition of a Sengoku daimyō.

Researchers identify it as Motonari's own handwriting.

In the process of the Edo-period storytellers narrativizing the core thought of the Sanshi Kyōkunjō, the 'three arrows' episode took shape.

The metaphor of a single arrow versus three bound arrows has parallels in East Asian classics (the Shi Pa Shi Lüe and others) and was likely drawn on as a form for telling the testament of a Sengoku daimyō.

The combination of Motonari's family situation, in which three sons appear, and the requirement of the telling, which sought a symbol of unity, brought into being the definitive version: 'Motonari hands over three arrows on his deathbed.

The 'three arrows' scene is not historical fact, but the fact that the three houses of Mōri, Kikkawa, and Kobayakawa did maintain firm unity and formed a great domain ruling ten provinces of the Chūgoku region is itself historical fact.

Motonari constructed the Two-River structure (Kikkawa and Kobayakawa) and built up an allied body centered on the main house — and this supported the Mōri house through the generation of his grandson Terumoto.

The three-arrows story is not the historical fact itself, but as a later story that symbolizes the conceptual power of Motonari as historical fact, it has continued to transmit the core of his thought.

In contemporary Mōri Motonari scholarship, the three-arrows story is positioned as an instruction tale formed in the Edo period and is not treated as a scene of historical fact.

On the other hand, the 1557 Sanshi Kyōkunjō is highly valued as the foundational thought and stands as an object of research as a representative example of the house-management documents of Sengoku daimyō.

To hold the perspective that distinguishes story from source while enjoying both is the path to a deep understanding of Mōri Motonari as a figure.