On the tanto recorded in the Meibutsu-cho as the Torikai Kunitsugu (鳥養国次), the NBTHK writes that the work of Rai Kunitsugu shows "the strongest nie of ji and ha within the whole Rai school"[[c:1]], and that single judgment carries the essence of the smith. The published sources place him at the very end of the Kamakura period, his activity reaching into the first years of Nanbokucho, where he stands beside Rai Kunimitsu, his slight senior, as one of the two masters who bring the Rai mainline to its close. His genealogy is unsettled across the published record: the usual account makes him a pupil of Rai Kunitoshi, one account a cousin of Rai Kunimitsu, others the son of Kunitoshi or Kunimitsu's younger brother. From of old he has been counted among the Ten Brilliant Pupils of Masamune (正宗十哲) and carries the name "Kamakura-Rai"[[c:2]], a name the published sources explain by the manner of the work itself.

That manner is a hamon the earlier Rai never showed: a midare-dominant temper of notare mixed with gunome, the nie thick and bright, kinsuji and sunagashi sweeping through the ha, yubashiri drifting along the habuchi. The kitae sets thick ji-nie over itame and weaves in frequent chikei, in places standing slightly. The recurring verdict of the published sources is that this is a workmanship "strongly shaped by the influence of Soshu-den"[[c:3]], and the comment of Honma recorded against another of his Juyo Bijutsuhin tanto holds the same line, that within the Rai school the nie of his ji and ha is conspicuously strong. Even an absence points the same way: compared with general Rai work, his ji shows fewer of the soft rai-hada patches typical of the school. The boshi of this register runs midare-komi or with a pointed tendency, often swept with hakikake.

Beneath the Soshu color the jigane stays Rai. The forging in his finest pieces is a packed ko-itame, the ji-nie fine and thick, chikei entering finely, and a pale nie-utsuri rising over the ji, the anchors that keep the work Kyoto. His most numerous surviving class is the wide osuriage mumei katana, often in a deep wa-zori with the chu-kissaki extended. On these blades a suguha-toned base mixes ko-gunome and ko-choji; ashi and yo enter long, thick and without pause; the nie sits deep into the ha, kinsuji and sunagashi run, and nijuba-like yubashiri plays at the edge. The deciding point is stated outright in the published sources: where the ji and ha are unusually bright and the nie strong, "if one fixes on the point that the nie-ashi stand out within the ha, an attribution to Rai Kunitsugu is judged proper"[[c:4]]. One Juyo katana is described as reading "just as though the midare he tempers on his tanto had been rendered on a long blade"[[c:5]].

His signed work is nearly all tanto and ko-wakizashi; the published sources repeat that surviving tachi are scarce, and that ken and yari survive only in the rarest examples. The tanto are signed below the mekugi-ana at the center of the nakago with a large, thick-chiseled three-character mei, while the slender signed tachi with high koshizori carry an elongated, finely chiseled, smaller signature that the NBTHK reads as his early hand, valued for showing the change of his manner over time. A minority of works keeps the older Rai style unaltered, a quiet suguha with ko-choji, the nie at ordinary strength; the tanto handed down in the Uesugi house is called "a calm register that holds faithfully to the Rai tradition"[[c:6]], and such work is noted as extremely rare for him. Dated pieces are nearly absent: the ken of Karyaku 2 (1327) is his earliest surviving date, worked, as with other smiths of the period, in Yamato-den; a tanto of Shokei 1 (1332) also survives, and Gentoku dates are known only from the old sword albums. On the tradition that he studied under Masamune the NBTHK itself is careful: since Kunimitsu too at times shows the same nie-strong manner, it writes, to affirm the pupil legend from the style alone would be "premature"[[c:7]].

The comparison that fixes his place is drawn against Rai Kunimitsu. Kunimitsu also left midare work beside his traditional suguha, but in his case, the published sources observe, the suguha far outnumber the midare, and "Kunitsugu is the opposite"[[c:8]]. One Juyo text goes further, judging that he carries the nie even beyond the nie-emphasized midareba of his senior, a manner the earlier Rai never had. Among the forebears of the line, Kuniyuki, Niji Kunitoshi, Rai Kunitoshi and Kunimitsu, he is the one who retains the least of the traditional Kyoto style, which is exactly why the old Masamune-pupil account drew attention. The judges also leave him room: various atypical pieces (変り出来) are acknowledged within his work, and his few signed tachi differ among themselves. With Kunimitsu he carries the Rai mainline to its close in early Nanbokucho, and the Kamakura-Rai name marks his position as the school's Soshu-facing edge.

Fujishiro grades him Jo-jo saku. One of his blades is a National Treasure and four are Important Cultural Properties, patrimony preserved wholly outside the market; beneath them stand fourteen Tokubetsu Juyo and forty Juyo, fifty-four blades in those two tiers, out of sixty-five designated works on record, twenty-nine of them signed against thirty-six unsigned. The Torikai Kunitsugu itself was certified Juyo Bijutsuhin in 1933. The provenance roll is of the first rank: the published sources single out the famous tachi handed down in the former shogunal house and in the Maeda house; another tachi, recorded in the Tokugawa Jikki, was presented by the shogun Tokugawa Tsunayoshi to Yanagisawa Yoshiyasu in Genroku 15 (1702); a katana passed from Matsudaira Nobuyasu, Ieyasu's eldest son, to his retainer Hiraiwa Chikayoshi; and tanto descended in the Uesugi, Asano, Okubo, Nabeshima and Ikoma houses and in the Yamauchi of Tosa, whose blade went to the shogunal house as a memorial gift in Kyoho 5 (1720). Of recorded whereabouts today, examples rest in the Tokyo National Museum, the Sano Art Museum and the Hikone Castle Museum. For the collector the picture is that of a major Rai master whose designated works are held far more often than they move: a mumei katana or wakizashi of the Juyo tier appears from time to time, a signed tanto only rarely, and a piece of the order of the Torikai Kunitsugu can only be awaited as an event.

On the tanto recorded in the Meibutsu-cho as the Torikai Kunitsugu (鳥養国次), the NBTHK writes that the work of Rai Kunitsugu shows "the strongest nie of ji and ha within the whole Rai school"[[c:1]], and that single judgment carries the essence of the smith. The published sources place him at the very end of the Kamakura period, his activity reaching into the first years of Nanbokucho, where he stands beside Rai Kunimitsu, his slight senior, as one of the two masters who bring the Rai mainline to its close. His genealogy is unsettled across the published record: the usual account makes him a pupil of Rai Kunitoshi, one account a cousin of Rai Kunimitsu, others the son of Kunitoshi or Kunimitsu's younger brother. From of old he has been counted among the Ten Brilliant Pupils of Masamune (正宗十哲) and carries the name "Kamakura-Rai"[[c:2]], a name the published sources explain by the manner of the work itself.

That manner is a hamon the earlier Rai never showed: a midare-dominant temper of notare mixed with gunome, the nie thick and bright, kinsuji and sunagashi sweeping through the ha, yubashiri drifting along the habuchi. The kitae sets thick ji-nie over itame and weaves in frequent chikei, in places standing slightly. The recurring verdict of the published sources is that this is a workmanship "strongly shaped by the influence of Soshu-den"[[c:3]], and the comment of Honma recorded against another of his Juyo Bijutsuhin tanto holds the same line, that within the Rai school the nie of his ji and ha is conspicuously strong. Even an absence points the same way: compared with general Rai work, his ji shows fewer of the soft rai-hada patches typical of the school. The boshi of this register runs midare-komi or with a pointed tendency, often swept with hakikake.

Beneath the Soshu color the jigane stays Rai. The forging in his finest pieces is a packed ko-itame, the ji-nie fine and thick, chikei entering finely, and a pale nie-utsuri rising over the ji, the anchors that keep the work Kyoto. His most numerous surviving class is the wide osuriage mumei katana, often in a deep wa-zori with the chu-kissaki extended. On these blades a suguha-toned base mixes ko-gunome and ko-choji; ashi and yo enter long, thick and without pause; the nie sits deep into the ha, kinsuji and sunagashi run, and nijuba-like yubashiri plays at the edge. The deciding point is stated outright in the published sources: where the ji and ha are unusually bright and the nie strong, "if one fixes on the point that the nie-ashi stand out within the ha, an attribution to Rai Kunitsugu is judged proper"[[c:4]]. One Juyo katana is described as reading "just as though the midare he tempers on his tanto had been rendered on a long blade"[[c:5]].

His signed work is nearly all tanto and ko-wakizashi; the published sources repeat that surviving tachi are scarce, and that ken and yari survive only in the rarest examples. The tanto are signed below the mekugi-ana at the center of the nakago with a large, thick-chiseled three-character mei, while the slender signed tachi with high koshizori carry an elongated, finely chiseled, smaller signature that the NBTHK reads as his early hand, valued for showing the change of his manner over time. A minority of works keeps the older Rai style unaltered, a quiet suguha with ko-choji, the nie at ordinary strength; the tanto handed down in the Uesugi house is called "a calm register that holds faithfully to the Rai tradition"[[c:6]], and such work is noted as extremely rare for him. Dated pieces are nearly absent: the ken of Karyaku 2 (1327) is his earliest surviving date, worked, as with other smiths of the period, in Yamato-den; a tanto of Shokei 1 (1332) also survives, and Gentoku dates are known only from the old sword albums. On the tradition that he studied under Masamune the NBTHK itself is careful: since Kunimitsu too at times shows the same nie-strong manner, it writes, to affirm the pupil legend from the style alone would be "premature"[[c:7]].

The comparison that fixes his place is drawn against Rai Kunimitsu. Kunimitsu also left midare work beside his traditional suguha, but in his case, the published sources observe, the suguha far outnumber the midare, and "Kunitsugu is the opposite"[[c:8]]. One Juyo text goes further, judging that he carries the nie even beyond the nie-emphasized midareba of his senior, a manner the earlier Rai never had. Among the forebears of the line, Kuniyuki, Niji Kunitoshi, Rai Kunitoshi and Kunimitsu, he is the one who retains the least of the traditional Kyoto style, which is exactly why the old Masamune-pupil account drew attention. The judges also leave him room: various atypical pieces (変り出来) are acknowledged within his work, and his few signed tachi differ among themselves. With Kunimitsu he carries the Rai mainline to its close in early Nanbokucho, and the Kamakura-Rai name marks his position as the school's Soshu-facing edge.

Fujishiro grades him Jo-jo saku. One of his blades is a National Treasure and four are Important Cultural Properties, patrimony preserved wholly outside the market; beneath them stand fourteen Tokubetsu Juyo and forty Juyo, fifty-four blades in those two tiers, out of sixty-five designated works on record, twenty-nine of them signed against thirty-six unsigned. The Torikai Kunitsugu itself was certified Juyo Bijutsuhin in 1933. The provenance roll is of the first rank: the published sources single out the famous tachi handed down in the former shogunal house and in the Maeda house; another tachi, recorded in the Tokugawa Jikki, was presented by the shogun Tokugawa Tsunayoshi to Yanagisawa Yoshiyasu in Genroku 15 (1702); a katana passed from Matsudaira Nobuyasu, Ieyasu's eldest son, to his retainer Hiraiwa Chikayoshi; and tanto descended in the Uesugi, Asano, Okubo, Nabeshima and Ikoma houses and in the Yamauchi of Tosa, whose blade went to the shogunal house as a memorial gift in Kyoho 5 (1720). Of recorded whereabouts today, examples rest in the Tokyo National Museum, the Sano Art Museum and the Hikone Castle Museum. For the collector the picture is that of a major Rai master whose designated works are held far more often than they move: a mumei katana or wakizashi of the Juyo tier appears from time to time, a signed tanto only rarely, and a piece of the order of the Torikai Kunitsugu can only be awaited as an event.