One Piece Chapter 7, page 18: Chapter 7: Friends

Koby stands at the dock, tears in his eyes, and salutes them with a "FWIP" sound. He yells, "THANK YOU VERY MUCH, CAP'N LUFFY! I'LL NEVER FORGET ALL YOU DID FOR ME!!!" Luffy smiles widely and waves, shouting, "WE'LL MEET AGAIN, KOBY!!" Zoro grins and says, "THIS IS A NEW ONE. A PIRATE BEING SALUTED BY THE NAVY! HAHA HA!" Suddenly, Ripper appears behind Koby and commands, "'TEN-SHUN!" He and all the other Marines salute Luffy and Zoro with a loud "FWIP!!" sound. Koby is surprised, uttering "HUH!?"