In this story we have learned that Magoroku Kanemoto´s blades are rated as saijō-ō-wazamono, that means they were extremely sharp. In the same category are blades by No-Sada*1 from the this story. Another saijō-ō-wazamono smith was Nagasone Okisato (長曽祢 興里), better known under his Buddhist priest name Kotetsu (虎徹, 1605~1678). Throughout his career he used different characters for the name Kotetsu, the earliest of which were (古鉄) – lit. “old iron” – because he was very skillful in processing old iron for his steel. Later, around the second or third year of Manji (万治, 1659-60), he changed the writing to a combination of the characters for “tiger” (ko, 虎 or 乕) and “piercing, penetrating” (tetsu, 徹). This writing goes back to a Chinese legend where once the mother of a man called Lî Gûang (李廣, jap. Ri Kō, ?-119 BC) was killed by a tiger. Lî Gûang wanted to revenge his mother and set out to the forests and mountains armed with bow and arrow. He was eventually able to catch sight of the tiger, drew his bow, and shot with confidence. But when he slowly creeped up to a few metres he realized that the tiger “had vanished” and that he pierced (tetsu, 徹) a large rock with his arrow. The moral of the story is that Kotetsu was inspired by this legend, choosing the above mentioned characters because he was convinced that you can achieve anything if you try with all your heart and soul.
Kotetsu was actually an armourer (katchū-shi, 甲冑師) from Fukui (福井) in Echizen province but went at the mature age of fifty to Edo to begin an apprenticeship as swordsmith under Kazusa no Suke Kaneshige (上総介兼重). The exact backgrounds for this are unknown but it is assumed that he had to change his profession because the demand for armours strongly declined in the peaceful Edo period. But maybe he was just looking for a new challenge in life in the boomtown Edo.
However, with his experience as an armourer and in the treatment of iron and steel, he made great strides as a swordsmith and soon his blades enjoyed a good reputation as being very sharp, even far beyond Edo´s borders. Towards the end of his career – adverstising was not longer necessary of course – he was visited by the young hatamoto Kugai Masakata (久貝正方, 1651-1719) in his forge. At that time, it is the Kanbun era (寛文, 1661-1673), very straight and hardly tapering blades with small tip were in fashion. The young Masakata had seen illustrious samurai walking through the streets of Edo with such swords and so he wanted to emulate them and have him a so-called Kanbun-shintō sword (寛文新刀) forged. Kotetsu accepted the order and went some time later to the Kugai residence in Edo´s Ichigaya-Kaga district (市谷加賀) to deliver the sword. Masakata drew the blade slow and carefully and examined it a with stretched out right arm as it was the sword etiquette. Fashion or not, he was totally unpleased with the shape and was concerned if such a blade could cut effectively at all. The young hatamoto was not embarassed and asked Kotetsu bluntly if the sword it sharp. The old smith was visibly annoyed that somebody dared to doubt the sharpness of his blades and so he grabbed the sword and left the house trampingly. He stopped in front of an old pine and raised the sword to an overhead position (daijōdan no kamae, 大上段の構え). With a loud combat cry he cutted down on a very thick branch of the pine. The branch was severed neatly and felt down on the ground, accompanied by a heavy noise. This noise was one half of the upper-most part of a ishidōrō stone lantern which was chopped by the sword too! “Gosh!,” said Masakata who hurried after Kotetsu to the garden. Somewhat sheepish he said: “This should be my main sword for all time.” Kotetsu replied sarcastically whilst returning the sword: “Well, I can´t deliver you a sword of whose sharpness I am not convinced…” Some see in this story another proof for the stubbornness of Kotetsu who was described as “being difficult,” but other see in this anecdote a try Masakata´s to subsequently haggle the cost down by criticizing the shape or the sharpness of the blade.
The blade in question came late into the possession of the Hosokawa family who had it slightly shortened from 2 shaku 3 sun (~ 69.7 cm) to the present-day 2 shaku 1 sun 2 bu (~ 64.2 cm). On this occasion, also the nickname of the blade – Ishidōrō-kiri (石灯籠切, lit. “Stone Lantern Cutter/Splitter”) – was engraved on the tang (see picture below).
Tang of the Ishidōrō-kiri, mei: „Nagasone Okisato Nyūdō Kotetsu – Ishidōrō-kiri“ (長曽祢 興里入道乕徹 石灯籠切).
One way to ascertain the sharpness of a blade are the often mentioned cutting tests, the so-called tameshigiri (試し斬り). At such a tameshigiri, one or more bodies of executed criminals – sometimes it was carried out also on living, death sentenced criminals – were placed to special standardized position to get “objective” results under standardized conditions. The result of such a cutting test was often inlayed in gold on the tang of the sword. Such an inlay is called tameshi-mei (試し銘) or saidan-mei (裁断銘). Tameshigiri were performed on different places and under different conditions and so also the tameshi-mei could be quite varied. But there was an official sword-testing department set up by the bakufu which was mostly held by the families of the Yamada (山田) and Yamano (山野).
Regarding Kotetsu, there was a close relationship between him, his then “employer,” the Nukada fief (額田藩, Hitachi province), and the Yamano sword testers Ka´emon Nagahisa (山野加右衛門永久, 1597-1667), Kanjūrō Narihisa (勘十郎成久, and Kanjūrō Hisahide (勘十郎久英, 1604-1694). Accordingly we find many tameshi-mei on blades of Kotetsu from that time, i.e. the Kanbun era. Although a smith of course benefited from such an “official evidence” of the sharpness or cutting ability of his blades, they were mostly performed not by order on the smith himself but by the owner of the blade. In addition, the entire whole procedure of a cutting test including a gold-inlayed tameshi-giri was not cheap and costed about 10 ryō. For comparison, the smith Inoue Shinkai (井上真改) took 11 ¼ ryō for a longsword, Tsuda Sukehiro (津田助広) took 7 ½ ryō, etc., that means the price of the cutting test was about as high as the price of the blade itself!
*1 In some copies of the Kaihō Kenshaku he is “only” ranked ō-wazamono.