Many of you might know the famous meibutsu Ebina-Kokaji (海老名小鍛冶, picture 1), a tantô which is famous since the Muromachi period as it was worn successively by each Ashikaga-shôgun. In an entry concerning New Year´s garments from the „Chôroku ninen irai môshitsugi-ki“ (長禄二年以来申次記, the second year of Chôroku was 1458) and the „Jishô´in-dono nenchû-kôki“ (慈昭院殿年中行事) we find namely the following entry about the eighth Ashikaga-shôgun Yoshimasa (足利義政, 1436-1490, r. 1449-1473): „This sword is called ebina-kokaji. It is used on the 30th day. It measures 1 shaku 2 sun 3 bu (~ 37,3 cm) and with the saya 1 shaku 5 sun 6 bu (~ 47,3 cm). Regarding its mounting, it has a tsuka and saya in nashiji and is mounted with kojiri and kashira made en suite of shakudô. The menuki depicted gilded kiri crests in the round and the kôgai too depicts the kiri crest. This sword is worn together with a formal hitatare (直垂) at New Year.“ However, the origin of the nickname „Ebina“ is unclear and the blade suffered a fire damage at the fall of Ôsaka Castle in 1615 and had to be re-tempered by the then best man for this task, Echizen Yasutsugu (越前康継). By the way, Yasutsugu made several copies of the blade when re-tempering it. One of the copies can be seen in picture 2.
Picture 2: Copy of Yasutsugu signed: „Echizen no Kuni Yasutsugu – Honda Hida no Kami shoji-nai“ (越前国康継・本多飛騨守所持内, „from the possessions of Honda Hida no Kami“), „nanbangane – Sanjô-Kokaji haku“ (なんはんかね・三条こかち迫, „[forged with] nanban-gane, tribute to Sanjô Kokaji [Munechika]“), nagasa 29,7 cm
The Ebina-Kokaji as seen in picture 1 measures today 9 sun 8 bu (~ 29,7 cm) but the „Kyôhô-meibutsu-chô“ (享保名物帳) lists it with a nagasa of 1 shaku 1 sun 2 bu (~ 34,0 cm), that means we have a difference of about 4 cm. Well, the blade has four mekugi-ana and was obviously shortened so this difference is nothing to write home about. But there is the oshigata collection „Hasegawa Chû´emon-katanaezu“ (長谷川忠右衛門刀絵図) from the ninth year of Genna (元和, 1623) which shows another Ebina-Kokaji (picture 3), that means the depicted blade is labelled „Ebina-Kokaji“, which has the same length as stated in the „Kyôhô-meibutsu-chô“, i.e. 1 shaku 1 sun 2 bu (~ 34,0 cm). This blade does not resemble the Ebina-Kokaji in katakiriba-zukuri as we know it today but is similar to another meibutsu of Munechika, the so-called „Takanosu-Kokaji“ (鷹の巣小鍛冶) or „Takanosu-Munechika“ (鷹の巣宗近) depicted in the „Kôtoku-katanaezu“ (光徳刀絵図, picture 4) of which the first edition was published in Tenshô 16 (天正, 1588). The latter is a hira-zukuri wakizashi with a sunnobi-sugata signed “Sanjô” and a nagasa of 1 shaku 5 sun 2 bu (~ 46,0 cm). Interestingly, the Takanosu-Munechika is also depicted in the „Hasegawa Chû´emon-katanaezu“, also with the same nagasa of 46,0 cm, that means the latter publication obviously did not mix-up the Ebina-Kokaji with the Takanosu-Munechika as it introduces both blades. Incidentally, Hasegawa Chû´emon was a renowned sword appraiser from the early Edo period.
Picture 3: The unsigned Ebina-Kokaji from the the „Hasegawa Chû´emon-katanaezu“. To the left we read the nickname „Ebina-Kokaji“ noted as (えびな小かち).
Picture 4: The Takanosu-Munechika signed „Sanjô“ from the „Kôtoku-katanaezu“.
The question now is, was the Ebina-Kokaji from the Muromachi-era records with a nagasa of 1 shaku 2 sun 3 bu (~ 37,3 cm) in katakiriba-zukuri signed „Munechika“ and shortened to 1 shaku 1 sun 2 bu (~ 34,0 cm) and later again to the present 9 sun 8 bu (~ 29,7 cm), or was it in hira-zukuri and shortened from 1 shaku 2 sun 3 bu (~ 37,3 cm) to 1 shaku 1 sun 2 bu (~ 34,0 cm)? And the second question is, when the Muromachi-era records referred to the latter blade as the Ebina-Kokaji, when did the present-day katakiriba-zukuri Ebina-Kokaji became the Ebina-Kokaji? The first time a drawing of the present-day Ebina-Kokaji appears is in the „Kokon-mei-zukushi“ (古今銘尽) which was published in Manji four (万治, 1661) (picture 5). But there are no whatsoever comments on its nickname and the name „Ebina-Kokaji“ does not appear at any point in connection to this blade. Incidentally, although the „Kokon-mei-zukushi“ was published in Manji four, it shows the features of the katakiriba-zukuri Munechika blade from before the fall of Ôsaka and its fire damage as the oshigata used for the publication date back to Keichô 16 (慶長, 1611). Well, the unsigned hira-zukuri blade depicted in the „Hasegawa Chû´emon-katanaezu“ is no longer extant today and from today´s point of view we have to end our speculations if it was the one mentioned in the Muromachi-era chronicles as Ebina-Kokaji. But I think I can rule out the approach that the signed katakiriba-zukuri was the one mentioned in the chronicles, namely by a reconstruction of the supposed original nagasa of 37,3 cm. When we take a look at picture 6 (top) it becomes clear that with that nagasa, the mei „Munechika“ would have been just above the habaki and on the blade itself. Also for a original nagasa of 34,0 cm as stated in the „Kyôhô-meibutsu-chô“ the signature seems too high. I would say that the original nagasa of the present-day katakiriba-zukuri Ebina-Kokaji was somewhere around 32 cm or below because it seems that the tang itself was not that much shortened. Another hint for the shortening of the 34,0 cm hira-zukuri is the continuation of the hamon from the ha-machi into the nakago. When you take a look at the reconstruction in picture 6 (bottom) you will see that the hamon would match well with the supposed original length of 37,3 cm.
Picture 5: The present-day Ebina-Kokaji as depicted in the „Kokon-mei-zukushi“ but without this nickname.
Picture 6: Blade length reconstruction of the present-day Ebina-Kokaji (top) and the Ebina-Kokaji from the „Hasegawa Chû´emon-katanaezu“ (bottom).
And I also think I can answer question two, i.e. when the present-day Ebina-Kokaji became meibutsu Ebina-Kokaji. It was namely Ôgi Hirokuni (仰木弘邦) in his publication „Kotô-mei-zukushi taizen“ (古刀銘尽大全) from Kansei four (寛政, 1792) who adopted the drawing from the earlier „Kokon-mei-zukushi“ but added the nickname „Ebina-Kokaji“. However, we don´t know if he mixed the blade up with the unsigned hira-zukuri just because of the same number of mekugi-ana and/or if he did not pay attention to the nagasa as mentioned in the Muromachi-era chronicles. Or maybe he was so convinced because of the presence of the signature „Munechika“ that this must be the famous blade worn by the Ashikaga-shôgun. In conclusion I dare to say that the present-day Ebina-Kokaji is not the Ebina-Kokaji worn by the Ashikaga-shôgun but I am not able to say if it was the one depicted in the „Hasegawa Chû´emon-katanaezu“.