Who is personal secretary from A Wild Sheep Chase and what is their importance?

As the right-hand man of the most powerful figure in Tokyo, the personal secretary of the Boss is a powerful man by himself. He dresses very formally, with gloves, a jacket, and a tie, and speaks with nearly perfect accent, although it is clear he is a foreign-born man. In addition, he takes his role very seriously. With the eminent death of the Boss at hand, the secretary takes it upon himself to find the source of his Boss' power, or his Will. In doing so, he has located the main character.