The 10th head of the Mitsui Family. He went to the U.S. to study banking in 1872. He came back to Japan two years later and joined Mitsui Bank (later, Sumitomo Mitsui Banking Corporation). He took over the head position of the Mitsui family in 1885 and earned the title of Mitsui Hachiroemon XV. As the head of the family, he made family rules called the Mitsui Kakei, founded Mitsui Gomei Gaisha (the Mitsui’s holding company), and introduced rijicho-sei system (having someone who was not part of the Mitsui family as the CEO of the Mitsui company). He oversaw the Mitsui zaibatsu with the first rijicho, Dan Takuma. He was given the title of danshaku (baron) in 1896.