One Piece Chapter 24, page 16-17: Things That You Can't Lie About

Kaya is outraged by Clahador's cruelty and screams, "THAT'S ENOUGH CLAHADOR!!! APOLOGIZE TO USOPP-SAN AT ONCE!!" Clahador calmly refuses, saying there is no need to apologize to an uncivilized person. He looks at Usopp and says he feels sorry for him because he must hate his father, a "dumb treasure hunter" who deserted his family and village. He mockingly suggests Usopp should have lied and said his father was a traveling merchant or not blood-related. Usopp, trembling with rage, growls, "I WON'T LET YOU SAY ANOTHER BAD THING ABOUT MY FATHER!

In a sudden burst of anger, Usopp lunges forward and punches Clahador squarely in the face, shouting, "SHUT UP!!!!" Clahador is knocked to the ground, his glasses flying off. Kaya gasps in shock, covering her mouth. Luffy watches with a serious expression. The three kids scream, "CAPTAIN!" in terror, while Zoro and Nami look on silently. Clahador, holding his bruised face, mutters, "UH.... GRH!! SEE... YOU'RE SO VIOLENT! LIKE FATHER, LIKE SON!!" Usopp stands over him, yelling, "SHUT UP!!!!