These were excavated from a Kamakura-period tomb. The large urn stores human ashes; it was fired at the Tokoname kilns in present-day Aichi prefecture. Alongside the ashes within the urn buried in the tomb were celadon bowls and dishes, the urn was buried in the tomb were celadon bowls and dishes, works of great refinement with ribbed designs of raised vertical bands. They are Chinese productions of the Longquan Kilns in Zhejiang Province.
 
YOSHIZAWA SatoruEnglish by Mary Lewine 
Buddhist Art Paradise: Jewels of the Nara National Museum. Nara National Museum, 2021.7, p.329, no.246. 

These objects were excavated in 1965 from a hill on the left side of the Hii river in the Izumo plain. It is reported that a large jar was placed within the square cavern of the tomb, which contained the ash of the dead, celadon bowls and dishes. The jar had reportedly been covered with a stone plate and buried under pebbles, over which the Sotoba-sign plate of the tomb was set. Both of the celadon bowls are deep and made in an elegant style. Twenty five lotus petals are depicted on the outer surface of the bowls. They are coated evenly with greenish blue glaze. The dish is not deep and has a wide mouth. The material is light-gray clay which was thickly coated with celadon glaze. The inside of the disk is decorated with petal-like stripes, and the design of a flowering plant is stamped into the bottom of the inside. All these celadon pieces are excellent both in shape and glazing. They were probably made in the Long-quan kiln in China and are among the best Chinese ceramics ever excavated in Japan. The big earthenware jar has a large shoulder and a short neck. It was probably made in an old kiln in today's Aichi prefecture. 
Masterpieces of Nara National Museum. Nara National Museum, 1993, p.132, no.106.