Bunzō

is a loan shark from the Akagi gang.

Background
He was sent with his brother, Senta to collect money Tsunade owes their boss. To blackmail her, they steal the First Hokage's Necklace, believing it still belongs to Tsunade.

Part I
However, it belongs to Naruto Uzumaki, who fights them to get the necklace back. Afterwards, they explain their position and Naruto agrees to collect on Tsunade's debt.