Luffy's famous Japanese words are as follows:

I'm a man who wants to be one piece!

ォレはになるだ male!

One day, I will gather a group of friends who are not lost to these people and find the world's first treasure. I want to be one piece!

ォレはぃつかこののにもけなぃをめて, て. One piece!

I've decided that if I want to be one piece, I have to fight for it, even if I die.

One Piece になるって, ォレはめた, んだから.

I'm Meng Qi D. Ruff! How could I lose to a pirate who gave up his name and fled from the sea? When a pirate gives up his name, it is no different from death! You can use this life to remember my name! Because I am ... the future one piece!

モンキ·D·ルフィ。 Before the name, I left the house, the sea, and the pirates. One piece's name is very famous, and it's very famous when it's given up and when it's dead! I've been a famous man all my life, and I'm the One Piece!

Extended information:

Luffy offered a reward of 1.5 billion Berry, which was called "straw hat". When I was a child, I ate rubber fruit by mistake, so I gained the ability to stretch freely like rubber. The dream is to find the legendary One Piece and become One Piece. He was inspired by Janks to have this dream. The mantra is "I want to be one piece". Oda mentioned that if the Straw Hat Pirates are a big family, Luffy is the four men in the family.

He has short black hair, which looks a little messy, and there is a scar under his left eye that he once scratched himself to show his bravery. Usually wearing a small red tank top and blue half-legged jeans. Wear sandals. I have been wearing a straw hat that once had red hair pinned on Luffy. Two years later, there were more "X" scars on his chest caused by the attack of the red dog, and he wore a yellow belt around his waist. Always have a confident smile on your face.