One Piece Chapter 41, page 12: To the Sea

Luffy looks down at Usopp with a wide, friendly smile and says, "YOU'RE ALREADY OUR COMPANION, AREN'T YOU...?" Usopp freezes in shock, his eyes wide as he stammers, "WHA...." Realizing they want him to join their crew, his face lights up with joy. He runs toward the ship, pointing proudly at himself and shouting, "I... I'M THE CAPTAIN RIGHT!?" Luffy immediately yells back from the deck, "NO WAY! I'M THE CAPTAIN!!" while Kaya and Merry watch them with warm smiles.