Developed in Nara in the early Muromachi period (1333-1573), the Haruta school was certainly one of the most important centres for the construction of armor in Japan. Armorers from this region specialised in the design of the kabuto, contributing to its affirmation as a key element of the Japanese armor. The most famous model attributed to this school is the akoda-nari kabuto, a particular type of suji-bachi kabuto with a characteristic rounded shape, higher in the back, which traces the profile of a pumpkin. The Haruta armorers developed then other helmet shapes more suitable for tosei gusoku and refined a certain taste for iron applications, which served both as decoration and additional protection. These applications, called kirigane, literally "cut metal", were born as simple iron lozenges, of various dimensions, and gradually refined themselves into finely worked designs. Thanks to the prestige accumulated over the decades, several members of the school were called to distant provinces to meet the commissions of other daimyō and it is interesting to note that the two main schools that developed from the Haruta, the Unkai and the Saika, used precisely the kirigane as a characteristic mark of their productions. We can identify some peculiarities among the various types of kirigane used in the regions of these schools: while in the Kaga area, where the Unkai school worked for the refined Maeda daimyō, the kirigane became very refined and three-dimensional, with motifs of clouds and cherry blossoms, in the Saika area we can feel a certain influence from Korean helmets and the iron applications, although complex, always remain flat and based on spirals and geometric lines.