The series of sea charts called Asia Kōkai-zu (Asia sailing maps) are sea charts that Japanese in the sixteenth and the seventeenth century made independently, while consulting European portolan sea charts, in order to travel to Asian countries. The area of the Asia Kōkai-zu covers Japan, the Korean Peninsula, China, Southeast Asia, the sea area of the Indian Ocean, and the East Coast of Africa. We can see the names of places, such as Kyūshū, Shikoku, Kyō, Suruga, Edo, and Ōshū. Ezo (Hokkaido) is drawn as a considerably large island. The names of the places between Kyūshū and Ryūkyū are particularly full. While the majority of existing Asia sailing maps were owned by families involved in the red seal trade during the early Edo period, this map is considered to have been handed down to Nagasaki Bugyōsho (the office of the Nagasaki government).