Rai Kunimitsu(来国光) is conventionally understood to have been the son or student of Rai Kunitoshi (来国俊). He worked from the end of the Kamakura era into the Nanbokucho era. The earliest signed work by him has a date of Karayku 1 (1326) and the last known dated example has a nengo of Kanô 2 (1351).
Rai Kunimitsu’s (来国光) workmanship is quite diversified. He produced the typically classical suguha as well as suguha mixed with ko-gunome and ko-chôji, notare mixed with gunome, gunome-midare, and others. Rai Kunimitsu (来国光) made tachi and tantô in a variety of shapes thus making him by far the most talented among the Rai (来)smiths in terms of broadness of repertoire and applicability.
The style and characteristics of the works of Rai Kunimitsu (来国光) changed over his lifetime. In fact, the changes toward the end of his career have caused some scholars to postulate that there might have been two generations of smiths by this name. This theory will require much more study in the future as there is no strong evidence to date to support it. That aside, there can be no argument that he worked in a variety of styles and produced swords with varying characteristics over his lifetime.
This tantô is a Jûyô Tôken tanto signed Rai Kunimitsu. It comes in an old shirasaya with a sayagaki by the famous Kanzan Sato. The following is a translation of the Jûyô Tôken zufu for this tantô:
Designated Jûyô Tôken at the 22nd Shinsa of June 1st the 49th year of Shôwa (1974)
Tantô, Signature: Rai Kunimitsu (来国光)
Measurements: Length: 22.4 cent.; Curvature: none; Width at Base: 2.1 cent.; Nakago Length: 9.0 cent.; Nakago Curvature: 0.3.
Characteristics: The construction is hira-zukuri with an iori-mune. The blade is rather small sized. The kitae is very tight ko-itame-hada with a mixing in here and there of slightly ô-hada that is covered in ji-nie. There is prominent nie-utsuri. The hamon is suguha, and near the monouchi, the yakihaba becomes narrow. There is a slight mixing in of ko-gunome. The habuchi is covered in ko-nie, and there is kinsuji activity. The bôshi is sugu with a ko-maru. The nakago is ubu, and the tip is kurijiri. The yasurime are kiri, and there are three mekugi-ana. On the sashi-omote is a three-character signature that extends downward to the nakago-jiri.
Explanation: Rai Kunimitsu is one of the representative smiths of the Rai School during the late Kamakura period. There are tachi and tantô works that retain their signatures, and although there are both normal sized works as well as rather large sized works, this tantô has a shape that is rather small sized. This same school specialized in the tempering of a suguha with a slight mixing in of ko-gunome, and their ji-ha is superb.
This tantô is also exhibited in the new publication by Kawashima san and Tanobe san called Nihontô Shûbi (A Collection of Beautiful Japanese Swords). The description of this tantô is as follows:
This tantô, during the feudal period, was in the possession of the Arima family, who were the lords of the Kurume fief in Chikugo Province.
It has a hira-zukuri construction, and the length is seven sun and four bu, which, for Rai Kunimitsu (来国光), is a small-sized blade. Moreover, because the sword is without curvature, we can surmise that this is an early period work of this same smith. Among the works of Rai Kunitoshi (来国俊), there are also those that were signed by Kunimitsu (daimei), as well as those that were signed and made by Kunimitsu (daisaku-daimei), though with Rai Kunitoshi signatures. The nakago is ubu, and the condition is also excellent. The yasurime are clearly visible, and while we believe that this is an early period work, the characters in the signature are powerful, even now the tagane-makura (ridge left on the edge of the characters from the cut of the chisel) also remains. The jigane is very tight ko-itame-hada that is thickly covered in minute ji-nie, and there is chikei activity, making it beautiful and powerfully vivid. The hamon is tempered in suguha with slight notare, which is the hamon that was handed down from Rai Kunitoshi. The habuchi is well covered in ko-nie, and the nioiguchi is tight, bright and vivid. With Rai Kunimitsu, many of his work have a bit of a tinge of the Sôshû-den similar to Rai Kunitsugu (来国次); however, this tantô has the feeling of following his father’s (Rai Kunitoshi’s) style of workmanship. The appearance of the shape is also close to that of Rai Kunitoshi’s elegantly refined construction.
This tantô has an accompanying koshirae, which we believe was made during the Edo period. The saya has a gold nashiji ground with a gold maki-e kurikara dragon executed on top of that. The exposed menuki are solid gold dragons, and the kozuka is shakudô with a nanako ground, and has a design of a dragon and tiger in gold iroe. The koshirae is extremely gorgeous, and it creates an impressive feeling.