Kuichigaiba (喰違刃) is a term used in the context of Japanese swords. It refers to a feature that appears in the blade of the sword. This feature is often seen in straight tempered blades (Suguha) made with the ""Nie"" method.
The term ""Kuichigaiba"" translates to ""eating different blades"" in English. It is named so because it appears as if a part of the straight blade is eating or overlapping with another part, creating a double-edged effect. However, it is not exactly the same as a double-edged blade (Nijūba), but it has a similar appearance in some parts.
This feature is mainly seen in the works of swordsmiths from the Yamato tradition. The Yamato tradition is one of the five main traditions of Japanese sword making, and it is known for its distinctive straight tempered blades.
Therefore, ""Kuichigaiba"" adds a unique and interesting visual effect to the blade, enhancing its overall aesthetics and value.