"Takehaya" is a pirate. He is named after the Japanese God of Sea and Storms. His men took 6 crew members of the USS Nathan James.
In S3E3, it is revealed that he was formerly an officer of the Japanese Maritime Self-Defense Force (Japan's navy, in other words).
It's unknown when he went rogue, but presumably he left when the plague hit Japan and started his pirate career.
As mentioned above, he is named after the Japanese God of Sea and Storms. Whether this is because of his former military experience or if his raids became so famous is yet to be known. His real name is revealed to be Kaito, but a last name is unknown. His wife is Kyoko.
- Takehaya, who is referred to as the mythological Japanese Shinto god of Sea and Storms, actually has a longer name. The full name of the god is Takehaya Susano no Mikoto, but chances are Takehaya's men just call him "Takehaya" for simplicity.