Oga Soku (大賀宗九)
Soku OGA (year of birth unknown -1630) was a Japanese trader. In the Azuchi-Momoyama and early Edo periods, Soku carried on overseas trade based in Hakata. Soku is known as one of the Hakata Sanketsu (the three outstanding merchants of Hakata), the other two of which are Soshitsu SHIMAI and Sotan KAMIYA. Soku's son was Sohaku OGA.
The Oga was originally of bushi (warrior) class and their family name was Ogami (or Okami), living in vassalage to the Otomo clan in Bungo province. Upon fall of the master's house, Soku became a merchant who carried on overseas trade in Keicho and Genna eras. At that time, following his Chinese friend's advice, Soku changed his family name from Ogami to Oga. In 1600 the Kuroda clan was transferred to Chikuzen Province, and somewhere before or after that Soku moved to Hakata to undertake construction of the public sector such as a castle and castle town, which was shared by Soshitsu and Sotan. Accordingly, Soku and the Kuroda family became closely united, and in 1621 Nagamasa KURODA granted a fief ('chigyo' in Japanese) to Soku, but Soku declined it due to his status. Designating his third son Nobusada (the future Sohaku) as his successor, Soku died in 1630.
The Oga family became head ('hitto' in Japanese) of all merchants of Hakata, and continued well into the Bakumatsu period (the last years of the Tokugawa shogunate). The 'Oga-kaku rank' was considered as the standard 'kakaku' (literally, family status or rank) among the merchants of Hakata.