What is Iriyamagata in Japanese Katana terminology?

The term "Iriyamagata" (入山形) refers to a specific shape of the tang end (Nakagojiri) of a Japanese sword, which is fashioned to resemble a pointed mountain shape. In this design, the blade side is longer, while the back side is shorter. On the other hand, if the tang end is pointed and the left and right sides are almost symmetrical, it is referred to as "Kengyou" (剣形). This terminology is used to describe the specific characteristics of the sword's structure, contributing to its overall aesthetic and functional design.