The Ichimonji school was established in the early Kamakura period and later many branch schools emerged, such as the Fukuoka Ichimonji, Yoshioka Ichimonji and Katayama Ichimonji schools. For inscriptions, they simply used the character "一 (one)" or their own names. This sword also has the inscription of "一" on the nakago (tang: the area that is inserted into the hilt of a sword). It features a wide blade, koshizori (a type of a blade curve where the deepest part of the curve is near the tang) and an ikubi kissaki (a short kissaki (tip of the blade) that is shorter in length than it is wide). This powerful appearance is one of the characteristics of the swords of the mid-Kamakura period. The grain of the ground metal is apparent with clear midareutsuri (a pattern that looks like a reflection of the hamon) while the hamon is an undulating chojimidare (a pattern that rises and falls along the blade). It clearly demonstrates the brilliant style of the Ichimonji school. The name "Imaaranami" seems to be derived from the vigorous hamon like raging waves.