One Piece Chapter 33, page 4-5: The Silent Man

Sham and Buchi fully commit to their rebellion, shouting, "You've been inactive for three years! Do you think you can still beat us, the 'Nyaban Brothers'?! We won't allow ourselves to be killed... for a stupid reason like 'a failed plan'!!" The other Black Cat Pirates whisper among themselves, agreeing that if the Nyaban Brothers gang up, even Captain Jango couldn't defeat them. Kuro calmly adjusts his glasses with a soft "Sret..." sound. With a fierce cry, Sham and Buchi leap at Kuro, yelling, "Instead of being killed by you silently, we might as well kill you first!! You're no longer our captain!

Sham and Buchi slash forward with a loud "SHAAAAAA...!!" but their claws strike only empty air. In the blink of an eye, Kuro has vanished, reappearing silently behind them. "Who did you say... you were going to kill?" Kuro asks coldly. The Nyaban Brothers freeze, sweat pouring down their faces in sheer terror. Jango is stunned, wondering when Kuro managed to get behind them, while Usopp gasps, "Ah... It's.. It's the 'Silent Step'!!" Zoro watches closely, noting, "What a weird looking weapon...