The circle indicates the time we discuss in this chapter.
Through the experience of the war of Jokyu-no-Ran (Chapter 10), the sword’s trend changed to a wider, sturdier, and grander style. The swords made around this time are called Ikubi-kissaki. Ikubi means a wild boar’s neck. Ikubi-kissaki style swords have a stout kissaki that looks like the boar’s neck.
The middle Kamakura period was the golden age of Japanese sword making. Many top swordsmiths created great swords during this time. Experts agree that there is no mediocre sword among Ikubi-kissaki swords
IkubiKissakiSword 
SUGATA (shape) ——–— Originally 3 feet or longer, therefore it is often shortened in later time. Wide width, thick Kasane (thick body) with Hamaguri-ha (蛤刃). Hamaguri-ha means the sword’s cross-section is shaped like a clam (see below). The difference in the width between the Yokote line area and Machi is minimal. Shinogi (鎬) is high, and shinogi width is narrow. The cross-section of an Ikubi-kissaki sword is shown below.
KISSAKI —— Ikubi-kissaki. Ikubi means the neck of a wild boar. It is thick, short, and stout looking. Kissaki is short and wide at the Yokote line. The illustration below shows an exaggerated image of an Ikubi-kissaki.
Hamon (刃文) —— Kawazuko-choji (tadpole-head shape pattern). O-choji (large clove- shape pattern), Ko-choji (small clove-shape pattern), a mix of O-choji and Ko-choji, or Suguha-choji. Suguha-choji has a straight line mixed with Choji pattern (clove-shape).
Kawazuko-choji O-choji Ko-choji Suguha-choji (tadpole head) (large clove) (small clove) (straight and clove)
Boshi(鋩子) ———Yakizume: the hamon ends almost at the tip of kissaki, no turn back.Sansaku Boshi: The hamon narrows at the yokote line, created by Nagamitsu (長光), Kagemitsu (景光), and Sanenaga (真長). See the below for Yakizume and Sansaku Boshi.
Yakizume 
Sansaku-boshi
Ikubi Kissaki Sword Smiths
Fukuoka Ichimonji Group (福岡一文字) —————Fukuoka Ichimonji Norimune (則宗) Kamakura Ichimonji Group(鎌倉一文字) ———— Kamakura Ichimonji Sukezane (助真) Soshu Bizen Kunimune Group(相州備前国宗)——– Soshu Bizen Kunimune (国宗)Bizen Osafune Group(長船)——————Bizen Osafune Mitutada(長船光忠) Nagamitsu(長光) Ugai Group————————————————————————- Ugai Unji (鵜飼雲次)
Osafune Nagamitsu(長船長光) From Sano Museum Catalogue (permission granted)
Osafune Mitsutada(長船光忠) Osafune Mitsutada(長船光忠) *Were family sword This photo was taken by my father and writings on the white paper were written by him.
Study of Japanese Sword 