Ōuchi clan
Tanegashima Island functioned as a relay station of one of the main routes of Chinese trade that connected Sakai to Ningbo. The Tanegashima clan cooperated with the Hosokawa clan, one of two powers who controlled Chinese trade. Tanegashima also engaged in trade with Okinawa-centered kingdom of Ryūkyū, which is attested by some letters given to Tanegashima by Ryūkyū in the 16th century. It is known that Japanese trade ships to Ming China exported Southeast Asian products such as pepper and sappanwood. They were probably obtained by the Tanegashima clan via Ryūkyū. Historians draw attention to a letter given to Ryūkyū by the Ōuchi clan in 1542, which requested Ryūkyū to detain Tanegashima's ships. The Ōuchi clan, who rivaled the Hosokawa clan in Chinese trade, seems to have intended to bar Hosokawa from trade.