In the 6th year of the Keichō era (1601), Tokugawa Ieyasu sent a diplomatic letter to Annam (present-day Vietnam) with the request to refuse the entry of Japanese ships without the Ieyasu’s read-sealed permits. On the other hand, the safety of ships with the red-sealed permits should be guaranteed by addressed countries. This is the origin of the Red Seal system of the Edo shogunate. This system was later expanded to apply to other Southeast Asian countries. This red seal permit uses the mulberry paper (otakadanshi) and states: “This is a ship from Japan to Kouchi (central to southern Vietnam). January 11th, the 19th year of the Keichō era (1614).” The vermilion seal of Tokugawa Ieyasu is affixed on the upper left. From the 13th year of the Keichō era (1608), the diplomatic affairs of the Edo shogunate were in the hands of Ishin Sūden. He was the supreme adviser to Ieyasu and Hidetada, the first and second shogun of the Tokugawa shogunate. Accordingly, merchants who wanted to voyage to Southeast Asia requested the issuance of to the red seal permits from Ishin Sūden through high-ranked officials such as Honda Masazumi, a chief vassal of the shogunate, and Hasegawa Sahei, the Nagasaki magistrate. In the Shōkoku-ji temple collection, there is a red seal permit by Ishin Suden. According to this ledger, known as the Ikoku Tokai Goshuin-chō (Important Cultural Property), permits dated January 11th in the 19th year of the Keichō era (1614) for voyage to Kouchi (central to southern Vietnam) was prepared and issued on the previous November 22nd–23rd. They were issued to the following seven people: Chinese named “Hau” (in Nagasaki), Chinese called “Sankan” (in Nagasaki), Chinese called “Yonkan” (in Nagasaki), Chinese called “Gokan” (in Satsuma, present-day Kagoshima), Chinese called “Rokkan,” Japanese named Funamoto Yashichi (Funamoto Yashichirō Akisada), and Portuguese named Monoeru Konsaru (Manuel Gonsalez, in Nagasaki). Each red seal permit was effective only for one round trip. The permit must be returned to Ishin Suden after the trip. If the permit holder did not go on a voyage in the specified year, he should return the permit without delay. This red seal permit is thought to be issued to one of the seven people mentioned above and was later returned to the issuer.