Okay, the user wants me to translate "inward curve" into Japanese. Let me think about the correct term here. "Inward" can be translated as 内側 (naikai) or 内部 (naikū), but in the context of a curve, 内側 seems more appropriate. "Curve" is 曲線 (kyokusen) or 曲がり (maguri), but 曲線 is more formal and technical. So combining them, 内側の曲線 (naikai no kyokusen) would be "inward curve." Wait, but maybe there's a more standard term. Let me check if there's a specific term used in engineering or design. Sometimes 内湾 (naikai) is used for an inward curve in coastal areas, but that's more specific. The user didn't specify the context, so sticking with 内側の曲線 is safer. Also, the user mentioned if the content is already in Japanese, leave it as is. Since "inward curve" is English, I need to translate it. So the translation should be 内側の曲線.