1604: The Establishment of the Itowappu Trade System
To curb Portuguese merchants' monopoly on profits from the raw silk trade, Tokugawa Ieyasu established the itowappu system, under which designated merchant guilds in Kyoto, Sakai, and Nagasaki collectively purchased imported silk and distributed it domestically. This regulatory measure shifted control over silk pricing to the Japanese side and helped curb the outflow of precious metals overseas.
Events this year
The shogunate designated Nihonbashi as the starting point for national distances and developed a transport system centered on the five highways.
Maeda Toshinaga created an organizational system combining approximately 10 villages in Noto, establishing the foundation of the tomura system, a unique peasant control mechanism that would characterize the Kaga domain.
For Chinese raw silk brought by Portuguese ships to Nagasaki, the shogunate granted the 'Itozaifumi Guild'—merchants from Sakai, Kyoto, and Nagasaki—exclusive rights to set prices and make bulk purchases, thereby controlling trade and protecting merchant interests.
Sources 長崎市出島復元整備室「出島の歴史（長崎年表）」
Starting from Edo's Nihonbashi, mounds were built on both sides of main roads at one-ri (approximately 4 km) intervals, with shade trees like Japanese hackberries (enoki) planted. These served as distance markers for travelers and as reference points for calculating palanquin and horse rental fees.
Sources 東京都板橋区「時代を紡ぐ 志村一里塚は動かなかった！」
Under Ōkubo Nagayasu, the Sado magistrate, the excavation of mine galleries (mabu) in the gold and silver mines proceeded under direct government administration. The Sado Gold and Silver Mine ruins are designated as national historic sites.
Sources 新潟県佐渡市「国指定 記念物：佐渡金銀山遺跡」