Chinjao was the 12th commander of the Happo Navy, but after Vice Admiral Garp caused his famed drill-shaped head to cave in, he lost his legendary strength, and access to the vast fortune buried inside the Jewel Ice Sheet. Losing everything and left with a broken heart, he gave up on piracy, and retired.
His position as the commander succeeded by his grandson, Sai, while his other grandson, Boo, became the lieutenant.
The Happo Navy consists of a large fleet of ships, situated in the New World, with the position of leader being passed down for 13 generations. The army was strong enough to survive an encounter with Vice Admiral Garp, and has amassed a great cove of treasure.
The Happo Army's signature combat technique is the Hasshoken, which allows the user to emit vibrations in a physical strike, breaking through shields and defenses and inflicting heavy damage. The vibrations can be imbued in virtually any melee attacks, such as fists, elbows, and kicks. It is similar to one of the applications of the Gura Gura no Mi.