Tsuwaji Island

• Japanese: 津和地島 (Tsuwaji shima)

Tsuwaji is an island in the western Inland Sea. Today administered as a part of Matsuyama City, historically too Tsuwaji was within the territory of Iyo-Matsuyama han. A major port, Tsuwaji was a frequent stop for daimyô on sankin kôtai journeys, and for numerous other official and unofficial travelers.

The island is roughly 13 km in circumference, and 3 km² in area. It lies roughly 28 km northwest of Matsuyama proper, and about 30 km south of Kure City in Hiroshima prefecture. The nearest neighboring islands include Nasake and Yashiro Islands to the southwest, and Nuwa and Nakajima Islands to the east.

While in premodern times ships generally followed closely along the coasts of Honshû or Shikoku, in the early modern period (that is, the Edo period), a greater volume of traffic began to sail through the deeper middle of the Inland Sea, and to stop at places like Tsuwaji which had not previously seen such traffic. Tsuwaji thus became a prominent link in a network of Inland Sea ports including Kaminoseki, Tomonoura, Mitarai, Shimo-Kamagari, and Yashiro Island, and a common place for ships to make harbor while waiting for favorable winds or tides. As early as the 1660s, it was identified as the busiest port in Iyo province, with some 500 ships each over 100-koku in size in port at once; in the 1690s, when Engelbert Kaempfer passed through Tsuwaji on his way to Edo, he noted that Tsuwaji had as many as 150 homes.

The lord of Iyo-Matsuyama established a teahouse on the island in 1635 (likely a reception hall for elite guests, akin to a honjin), and named retainer Yahara Sanozaemon his deputy (nashiro), to oversee such matters. The Yahara family remained influential figures on the island throughout the Edo period, serving as district magistrates (gun bugyô) for much of the period. The Yahara-ke goyô nikki collects records of much of the magistrates' official matters from 1768 into the 1850s or 1860s.