Kunikiyo was the fourth of the six brother-masters of the early school in Yamashiro, working in the opening years of the period. The published sources set him in that celebrated company. He was a son of Kuniie, with Kunitomo, Hisakuni and Kuniyasu as his elder brothers and Arikuni and Kunitsuna as his younger, and all six are recorded among the , the smiths who forged in rotation for the cloistered court of Go-Toba-in (後鳥羽院). Very little of his work survives with a signature. One entry states plainly that "extant signed pieces are few, numbering only two". Those two signed are known: the Aoyama-family , designated an Important Cultural Property, and a from the Unshu Matsudaira house recognized as a before the war. Beside them his name is carried by a small group of , judged to him.
His hand is the bright, quiet manner of early . The is a closely forged , in places running a little or mixed with larger grain. It carries abundant , and on the appear frequently. The published sources call that steel notably bright, and on one blade a faint stands. Over this he tempers a -toned , shallowly in places, worked with , and . enter, the is deep and bright, and the is well adhered, with fine and running through. The goes straight to a or an and returns.
Within that -based edge the published commentary singles out one piece of scenery on the . Patches of toward the gather there into a -like double line, recorded on both its and its entries. It is a restrained feature, in keeping with a smith whose whole character is calm rather than showy.
The published sources read Kunikiyo closest to his brother Kuniyasu. On the signed of the Unshu Matsudaira house the commentary finds the temper "on the whole resembling Kuniyasu". The two signed differ in the cut of their signatures, yet both carry a dignified , and Honma adds that blades attributed to Kunikiyo can almost all be appraised as work. On one of the the tightly packed intervals of the and an tendency of the are held to share "a thread of affinity with Kuniyasu". That affinity, set on the bright , carries the attribution where the signature is gone. The sources affirm such a blade as work that "at a glance can be appraised as of the early ".
Kunikiyo is graded sai-jo by Fujishiro. He has no National Treasure. Four designated works stand on record: the Aoyama-family Important Cultural Property , the prewar , one and one . The descended through the Sakai house of Himeji, and the published sources call it a superior blade whose "glittering within the temper is especially magnificent". Of recorded whereabouts, one blade is held by the Fukuyama Art Museum. With so few works on record and most of them long held, a signed Kunikiyo comes to light only rarely, and a privately held example of either his signed or his attributed is among the rarest things a collector of early Yamashiro could encounter.