Kaku (カ ク Kaku?) Appeared first seen as one of the five greatest carpenters at Galley-La Company in Water Seven. He was the one who checked the state of the Going Merry ship belonging to the Straw Hat Pirates. He also told me that the Going Merry had very severe damage and it was difficult to repair it, so it was recommended to replace it with a new one.
As time went on it was known that he was a CP9 member disguised as a carpenter, to look for the Pluton blueprint from Iceburg.
Appearance
Kaku has big eyes and a long nose like Usopp, this makes people wrong like Roronoa Zoro who thinks Kaku is Usop. But there is a difference if Usopp's nose looks round at the end so Kaku looks at the box at the end. His hair is golden and short blonde.
While working at Galley-La Company he wore an orange high-collar jacket and blue sleeves, jeans, white sneakers, and a white hat with Galley written on the front of his hat. But when he became a CP9 his appearance remained the same except that everything was all black.
Personality
At the Galley-la Company he was a passionate and cheerful person. He was nicknamed a mountain wind because he always shot high like flying. Then when becoming a CP9 is the most quiet and cold-faced member than the others. When defeated by Zoro he showed his sportsmanship and claimed to be defeated in the air.
He also seems to be the only one of four members disguised in Water 7 who expressed some remorse that he could not return to the way he had lived for the past five years.
Source : WIKIA ONE PIECE