The Kogarasu Maru
The Kogarasu Maru – a double-edged Katana – is also called the Little Crow. It is a distinct Japanese Katana believed to have been crafted by Amakuni.
Known as a legendary smith, it is said that Amakuni made Kogarasu Maru in the 8th century CE. The sword was also said to be a double-edged Katana.
Currently, the Kogarasu Maru can be found with the Japanese Imperial Collection. Its Tang is not signed like other classic swords, but the blade is claimed to have been created in the early Heian period. It was also possible to have been made in the late Nara period.
There are two other Kogarasu Zukuri that exists from the period. However, there are other similar types of blades crafted throughout history.
What was the Original Version of Kogarasu Maru?
The original version of this blade appeared like a European broadsword or Chinese Jian. The sword had one side sharpened, while the other side only had its tip sharpened the same way.
It was common to find a Bo-hi on the unsharpened area. This was called the Koshi Hi. Another feature would be the thin Bo-Hi that ran the blade’s length. This was the Soe Hi.
This sword had this shape for about a hundred years in the year 700 AD. The swords created in the country were almost the same as those made in China.
During that period, it was common to import steel and swords from China. And it was a sword that was an inspiration for the Moroha Zukuri. It is a kind of sword that’s just like every other ancient sword – it was straight-bladed.
Walking their Own Path
Things changed during the fall of the Tang Dynasty. It was when Japan completely disconnected itself from the Chinese. This allowed them to redefine the dimensions and geometry of their techniques. It also led them to improve their heat treating and smelting techniques.
The heat treatment method is the main factor that led to the curvature of Japanese swords.
What are the Physical Aspects of the Kogarasu Maru?
The Kogarasu Maru is styled with a curved and double-edged blade. Its length is about 62.8 centimeters long.
One of the blade’s edge is shaped like a Tachi. But the difference is that its tip is balanced, and both blade edges are sharp. An exception would be the 20-centimeter concave edge close to the hilt which is a rounded area.
One Koshi Hi type of groove extends from the Tang to its transition point. This is where the blade turns into a double-edged piece. It is also invariably followed by the Soe Hi.
The hardening method yields a straight line which is the Suguha Hamon. This is on both sides of the sword’s blade.
Another Name, The Kogarasu Zukuri
The Kissaki Moroha Zukuri swords like the Kogarasu Maru, are also called the Kogarasu Zukuri. This is because the blade is shaped distinctly, and is known for its unique Sugata.
All about the Kogarasu Maru
The Kogarasu Maru that exists today is forged in the style of Kissaki Moroha Zukuri. It was a favored blade shape during the Nara period. Yet swords of that time featured a shorter cutting edge at the back.
The Kogarasu Maru also had better quality than swords of that time. It was more notable than the Shousouin and is on a level with the earlier Kyushu pieces. These works include those from the Ko Naminohira School or from Bungo Yukihara.
Who was Amakuni the Swordsmith?
As mentioned, the Kogarasu Maru has always been linked to the legendary Amakuni. Ise Sadatake writes something about this, “The blade is Mumei. And due to the Tang’s bad condition, no file marks are visible”.
Despite this, the Honami clan, as well as other sword appraisers agree that it was Amakuni’s work. An artwork of Konami Kouetsu depicts the sword with a signature and date. The artwork was published once more in Tsuguhira Oshigata.
One should note that Koetsu’s drawing of the Tang and Blade are similar to the existing Kogarasu Maru in terms of proportions and length. Other similarities include the positions of the Ha Machi, Mune Machi, and Mekugi Ana.
Mei on the Tang of Kogarasu Maru
The sword’s Tang is somewhat corroded so its signature can’t be seen today. This does not mean that a visible Mei was absent during the time of Koetsu. Specifically, it was during the early Edo era.
This also explains the incomplete and very fine reconstruction of its Mei in the Honami Koetsu Oshigata. The Mei reads “Amakuni”, and after this are unreadable characters. Though, the Taiho period is noted here, as well as the characters utilized during the period of Amakuni.
The year on the sword is only partly seen. All that is visible is a single curved stroke on its bottom right. Some assume that it is a character for 2 or 8. But since the Taiho period only lasted for four years, the assumption of 8 can be dropped.
Amakuni was also dated in classic sword documents to the Taiho period. This would somehow tally with the date on the Kogarasu Maru.
Mountings of the Kogarasu Masu
The Kogarasu Maru did have its own set of mountings, Ise Sadatake states that its metallic fittings for suspensions were broken. Not only that, but its hilt wrap was loose as well.
The mounting is claimed to be from the 2nd year of Onin in 1468. It means that there was a high chance that the original was destroyed during the fire in the course of the war.
A Count named Muneshige also said that the mount was highly damaged when he purchased this. He also claimed to have restored this since it was a gift to the Emperor. It was in such a bad condition and he could not hand this over to the Emperor in such a state.
Who was Amakuni Yasutsuna?
Amakuni Yasutsuna was known as a legendary smith. He’s considered as the creator of the first single-edged longsword or Tachi.
He led the group of smiths hired by the Japanese Emperor. They created weapons for the emperor’s warriors. Amakura was his son who succeeded in his work.
There are almost no modern samples of his signed works. Though legends state that the double-edged Katana, the Kogarasu Maru, was forged by him.
The real author of such work is still unknown. Yet the work displays similarities to creations of different Yamato schools. This is why it is thought as an early sample of craft from this province.