Kanshichirou Yaguruma (カンシチロウ･ヤグルマ), sometimes known as Yagu (ヤグ) is a Japanese immigrant and the elderly primo voto of the Martillo Family. In November 1930 he became a complete immortal after accidentally drinking Szilard Quates' Cure-All Elixir. He is the one responsible for introducing Firo Prochainezo to the Martillos after Firo tried to pickpocket him as a child, and he has also taught Firo some martial arts and Japanese.