The bakufu discovered this subterfuge when Sō Yoshinari’s retainer, Yanagawa Shigeoki, petitioned to leave the service of the Sō house and become a shogunal hatamoto. Rather than execute the daimyo for this impropriety, however, he dispensed the relatively lenient sentence of a sharp reprimand, while Yanagawa bore the full brunt of the bakufu’s ire. Furthermore, Korean trade was placed under the supervision of Zen monks appointed by Edo, who took up residence in the Iteian hermitage on Tsushima. The Sō family, however, retained their monopoly on trade and diplomatic relations with Korea. This was a remarkably lenient punishment, considering the fact that other daimyo had been forced to commit seppuku on less severe charges. The only explanation is that the shogun valued the Korean trade and was not willing to lose it by removing the So, the traditional mediator of trade with the peninsula. A description of the end of this affair can be found in the diary of Couckebacker: see NKKS Vol. I, 234–35: April 25, 1635. An English account of the “Yanagawa affair” can be found in Jurgis Elisonas, “The Inseparable Trinity: Japan’s Relations with China and Korea,” in The Cambridge History of Japan, Volume 4: Early Modern Japan, ed. John Hall (Cambridge: Cambridge University Press, 1991), 235–300.

6. Marius Jansen, The Making of Modern Japan (Cambridge: Harvard University Press, 2000), 64.

7. For a good bibliographic essay on Japanese scholarship in the field of economic history, see Yamamura Kozo and Susan Hanley, “A Quiet Transformation in Tokugawa Economic History,” The Journal of Asian Studies 30: 2 (1971): 373–384. This essay is over twenty years old but is still extremely relevant, especially in outlining the shift away from a Marxist approach to economic history that occurred in the 1960s.

8. I have chosen to leave the terms shuinsen and shuinjo untranslated since the alternative is an unwieldy English term such as “red-seal ship.” A shuinjo refers to an official document issued by the shogun (or Hideyoshi earlier) and is characterized by his official vermillion seal. Therefore, the ships that were officially sanctioned to trade overseas are called shuinsen, or “red-seal ships.”