The ninja looked visibly surprised at this (his eyes widened - they really did) and he stood staring at the closed door a few moments before knocking again. "Usopp?" he asked, trying to sound the least threatening he could. "It's all right, Usopp. I'm not going to attack you."

He thought of asking if the other man wanted him to change out of his current outfit but, truth be told, he didn't really want to.