After Otagaki Rengetsu poem carved pottery cup #5487-1

width: approx. 10.8cm (4.25in)
height: approx. 7cm (2.76in)
weight: 318g
poem: It appears to be a poem about the moon at night, but it could not be identified.

Rengetsu ware
Characteristics of Rengetsu ware include decoration with waka poems composed by Rengetsu herself, the frequent production of utensils related to sencha tea culture, and the use of hand-building techniques such as tezukune (hand-forming) and molds rather than strictly wheel-thrown forms. The clay used was sourced from the eastern Kyoto (Rakuto) area. Both unglazed and glazed examples are known.

There are also works in which vessels made by potters other than Rengetsu were later inscribed with her poems. For firing, she relied on kilns such as Awataguchi ware, Kiyomizu ware, and the potter Kuroda Koryo.

Specifically, figures known to have produced such imitative works include the farmer Yoshida Yasu, Tarumi Fumiko, and Kuroda Koryo, who was permitted to call himself the second Rengetsu. It is said that Rengetsu welcomed these imitations, remarking that if people could make a living through copies of her work it would be a good thing, and she even carved her own poems onto such pieces so they could be sold.
※Based on the inscription, this piece appears to be Kiyomizu ware bearing a poem by Rengetsu.