I've always admired Ito's work -- my Yakimono Sanka book, first published in 1995 by Kogei Shuppan, includes a photo of a small Ito sake cup. Ito's mumyoiwork, with its brilliant red and black contrasts, is one of the hidden treasures of Japanese yakimono. And on top of that he arguably makes the best neriage marbled wares in the world that I've seen, certainly his is THE BEST in Japan. I was expecting a Bizen or Setoguro LNT this year, thus the Ito designation was actually a breath of fresh air for the yakimono world. The reason being it's the first for mumyoi and will certainly boost the image of the style for Ito and the other mumyoi-yaki potters. Also, Ito is not "related" to any major teachers, nor was his father a LNT. Ito earned it on his own just like the first wave of LNT potters.

Below is a very brief English excerpt from a pamphlet that is handed out at the Seksui kiln:

MUMYOI POTTERY SEKISUI KILN
"The fine ceramic wares created in the Sekisui family kiln are made form a special red potter's clay known as mumyoi. The clay is extracted form gold and silver mines located on Sado Island. The craftsmanship that goes into every piece of mumyoi pottery has been passed from father to son for over 150 years. The Sekisui kiln is located in the town of Aikawa on Sado Island. The kiln's history began when Tomisaburo Ito founded the pottery during the Tempo Era of the Edo Period, more precisely Tempo 2 (1831). Tomisaburo is known as the 'father of the Sekisui kiln' and the first muyoi potter."

A little bit more about mumyoi and Ito. The current Sekisui was born Yoichi, "yo" being the kanji for kiln. He was the first in his family to get a formal education, graduating from the Kyoto Technical University with a degree in ceramics in 1966. In 1972 his work was accepted into the elite Japan Traditional Arts and Crafts exhibition and the following year he won the grand prix in the 2nd Japan Ceramic Art exhibition.

He took the name Sekisui V in 1977. Around that time he started experimenting with firing an anagama in a reduction mode to bring about the black and red contrasts that he is now so well known for. It has been compared to Yayoi period wares, which often display the same effects. He started creating his neriage around 1980.

The Ito family is not the only mumyoi potters on Sado. In fact, that is where another Living National Treasure hails from -- Miura Koheji, the LNT for celadon. His family dates back to Meiji 6 (1873). The first Miura was also named Koheiji and later took the name Jozan. There are twelve active kilns in Aikawa today, and between 20-30 in all of Sado. [Yellin]

The ceramic artist Itō Sekisui V was born and raised on the island of Sado. How does he feel about his home? “To put it briefly, I take this land very seriously,” he says.

Itō Ihei, an ancestor of the “living national treasure” Sekisui, moved to Sado from the mainland around the time of the 1640 gold rush, when the island’s gold and silver mine was flourishing. His son Jinbei built a kiln and started making the bellows and tuyère pipes used in gold smelting, as well as unglazed ceramic items for everyday use. Through the generations, the family came to produce more sophisticated tea bowls and plates. In the nineteenth century, a kind of red clay called mumyōi was discovered in the gold mine. Itō Tomitarō, the ninth generation of the family that started with Ihei, fired the clay at high temperatures to create the ceramic style known as mumyōi-yaki. Shortly after the Meiji Restoration in 1868, Tomitarō took the name Sekisui, which has now been passed down for five consecutive generations.
Today’s Sekisui V has deep roots in Sado, and the family has produced ceramics for centuries.
“It’s continued for so long—thirteen generations—that I can’t quit today. Both mumyōi-yaki and Sado are heavy presences for me.”
Mumyōi, red clay taken from near the veins of the mine, is rich in iron oxide. It has long been used in China as a traditional medicine for stanching bleeding. In Japan it is only found near the Sado gold mine as a byproduct of mining. If fired at high temperatures, it becomes very hard, giving off a clear, metallic sound when struck.

“In Chinese traditional medicine, iron is an important element, and it is particularly abundant in mumyōi,” Sekisui says. “The clay feels dry like sand. Some forms of ceramics use clay with stones containing radium. Perhaps when they first made mumyōi-yaki, they were seeking to achieve a similar kind of medicinal effect.”
Sekisui V was born as Itō Yōichi in 1941. Before he entered university, his father died. This meant that he learned the art of making mumyōi-yaki from his elderly grandfather Sekisui III. Forced to immerse himself in the family trade at a tender age, he started work in earnest in 1966. Japan’s economy was booming, as was the Sado tourist industry. Mumyōi-yaki items were highly popular in the island’s tourist shops, but Yōichi did not get carried away by this, setting his sights on reaching a higher level as an artist.
Mumyōi-yaki is known for its gorgeous red color. Yōichi’s predecessors valued a beautiful red that calls to mind Chinese-style shudei (vermilion earth) works. However, the high level of iron oxide in mumyōi-yaki means that it turns black where it is touched by the flames in the kiln. This yōhen wood-firing effect was traditionally considered to result in a failed piece, but Yōichi thought that burning some parts black might set off the red to greater effect. Using the yakishime technique of firing unglazed wares at extremely high temperatures, he created his own distinctive series with a striking contrast between the two colors.
“Depending on where potters place the works in the kiln, they can have a good idea of what kind of yōhen will happen,” Sekisui says. “However, it is not possible to do this with a precise level of control over the outcome. This is the interesting thing about pottery. With the color changes, I’ve added range to my work.”
Following the creation of his innovative two-color series, in 1972 Yōichi had his first work accepted for inclusion in the annual exhibition of the Japan Kōgei Association, which supports traditional crafts. His reputation grew, and in 1977 he became the fifth in his line to take the Sekisui name. However, he still sought to break new ground. His next challenge was to knead together different colors of clay, a technique known as neriage, so as to produce a pattern. In 1985, his mumyōi works in this style won the Grand Prize and Prince Chichibu Cup at the Japan Ceramic Art Exhibition.
His early neriage pieces were simple patterns based around lines. Today he has advanced to flowers, fish, and birds, created by layering clay so it looks something like rolled sushi, cutting through it, and lining up the cross-sections.
Designation as a living national treasure in 2003 did not slow him down either. In 2009, he applied rhyolite and granite from Sado, a volcanic island, to a new mumyōi-yaki series he called Sadogashima, after the island’s Japanese name. The use of natural minerals gave the works a rough, unsophisticated power.
Although he speaks of the heavy importance he places on Sado and his family trade, Sekisui displays a freedom and lightness in his attitude to and thinking about his creations. He is not tied by tradition and does not cater to his admirers.
“It might sound like I’m showing off a little,” he says, “but we creators trust our own sense and work on the pieces that we want to. It’s better if people ultimately accept that. My basic thinking is to create by myself. I’m not just making something; I’m creating my own work. My family has worked with mumyōi clay for generations, but within that genre it’s important for me to exercise my originality.”
Sekisui has exhibited overseas on numerous occasions and institutions like the Metropolitan Museum of Art in New York, the Smithsonian Institution in Washington DC, and the Victoria and Albert Museum in London include his works among their collections. He is still full of energy. In 2017 his solo exhibition Red Soil was held at the Onishi Gallery in New York after seven years of preparation.
Sekisui feels the pressure of his heritage, but seems to use it as a springboard for vigorous creativity. I ask him about Sado again and he responds, “When I think about what the island possesses to convey to the world, the answer has to be culture.
“Sadogashima has been an island of exile since ancient times. People who defied the central government were sent here, including Emperor Juntoku, the Buddhist priest Nichiren, and the playwright Zeami. But what was unusual was that they had to be self-sufficient. So long as they didn’t leave the island, they were free to marry or apply their talents to business. As a result, the manners and customs of the nation’s center were conveyed here, fostering a kind of highly cultured freedom, which took firm root. If my works have inspired any interest in Sadogashima, I would like to tell people that it is not the kind of place that you can get around and understand from a day trip alone.”
https://www.nippon.com/en/guide-to-japan/b08505/a-master-in-red-clay-ceramic-artist-ito-sekisui-v.html?pnum=2

See: Frederick Baekeland, ed., Modern Japanese Ceramics in American Collections, pg. 153