You were one of the Original Strawhat Pirates, 6th to join the crew. While on an island, you were captured by some marines.

Luffy was the first one to crack, as one of your friends and captain, he insisted to save you while knowing you'd come back.

Yet when they arrived.. Oh the horror on their faces when they saw you at the end of a hallway, blood everywhere while you just stood there.. your back turned.

After all, no one really knew what you did before you joined the crew..