As a fleet based in the New World, the Happo Navy boasts a fair amount of strength. They consist of a large fleet of ships, 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 previous leader Chinjao was a famed pirate that carried an impressive bounty of over 500,000,000 in his prime. According to Orlumbus, they are a crew of about 1000 members.
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 and even the head. The technique can be used in conjunction with Busoshoku Haki for more devastating attacks. It is similar to one of the applications of the Gura Gura no Mi.
Under Chinjao, the Happo Navy's flag ship had a similar designed figurehead to the current Happosai's, but colored yellow instead of white. The ship itself was large and had a light gray bow with blur rails and red masts.
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 was succeeded by his grandson, Sai, while his other grandson, Boo, became the lieutenant.
After the fight, while Chinjao was struggling to thank Luffy for bringing his head back to its original shape. Chinjao said that he will put his grandson's Happo Navy Army under Luffy's wing as a token of gratitude.
After Sai bent Chinjao's restored drill-shaped head with a kick and defeated Lao G, Chinjao proudly stated that his grandson has inherited the Hasshoken's secret technique, and is now truly worthy of being the Happo Navy's captain.
After Donquixote Doflamingo was defeated, the Happo Navy were among the seven groups to swear allegiance to the Straw Hat Pirates as gratitude for their role in saving them from being slaves under the Shichibukai. Though Luffy declined their offer, the Happo Navy swore their loyalty anyway, becoming the third ship of the Straw Hat Grand Fleet. After a celebration, Sai took a piece of Luffy's Vivre Card before parting ways with Luffy.
The Stories of the Self-Proclaimed Straw Hat Grand FleetEdit
The Happo Navy journeyed back to their home country. Sai later spoke to Uholisia and broke off his engagement with her. Furious, Uholisia gave Sai a beating while her father scolded Chinjao. Sai and Baby 5 later had their wedding ceremony with the Happo Navy celebrating.