The owner of a gallery selling Japanese art that is opening in two weeks on 78th Street at Madison Avenue is backing into her new project.

Joan Mirviss, a private dealer of Japanese fine art in America, Japan, and Europe will be turning her art dealing business, Joan B Mirviss Ltd., into a gallery. “I’m doing everything backwards, as I always have done,” the Japanese specialist of 30 years said. “This is a new challenge.”

Two pieces are seminal in the career of Ms. Mirviss, who sells to more than 45 museums and has accrued several hundred avid clients who buy art from her on a regular basis. Both decorate her home: a clay vase made by Kamoda Shoji, considered the most important Japanese artist of the 20th century, and a sliding door panel mounted as a screen.

The ceramic pieces created by Kamoda, who died at 49 and whose top ceramics sold for as much as half a million dollars in the 1980s, are in such demand because each one is unique and his style changed every four to five months.

Ms. Mirviss, exclusive representative for more than 30 artists, had seen the “Purple Vase” (1968) in a solo exhibition of Kamoda’s work in the National Museum of Modern Art in Tokyo in 1983. “I decided if I could ever get that one piece, I would,” she said.

In 1996, an art dealer friend of hers in Japan alerted Ms. Mirviss that the clay work was for sale. She immediately purchased it for about $35,000. Since then, the ceramic piece has been hand-carried back to Japan in order to appear in a 2005 traveling exhibit in six different museums. “This piece served to cement a lot of relationships for me in Japan,” Ms. Mirviss, who has fielded and rejected several offers to buy the vase, said. The Kamoda vase resides in the living room along with the colorful and delicate-looking Japanese screen. The screen is a much more recent purchase. An artist who did not become successful until the end of his career, Tanaka Isson, painted the scene of nature in the fall that decorates the screen.

Tanaka painted the sliding doors sometime between 1945 and 1946, a period when there were barely any artists working in Japan. “He infused it with a startling modernity and truncated position,” Ms. Mirviss said. “You are suspended as a viewer — nothing is grounded in space. It’s autumn and everything is about to fall apart; there’s this luxurious foliage, but also sign of decay.”

Bought from a dealer in Kyoto about two years ago, the screen, part of a set of four, is not a typical purchase for Ms. Mirviss. “It’s not from a period I normally collect,” she said.

Ms. Mirviss said she thinks it’s unethical to personally collect what she sells, because then she would not be selling the best art but rather keeping it for herself. “As a dealer, I can’t collect what I deal,” she said.

Paul Vincent Wiseman designed both the living room and the library, along with the sun-room where Ms. Mirviss and her husband, Robert Levine, a retired partner at the law firm Davis Polk & Wardwell, throw parties to watch the Macy’s Thanksgiving Day Parade. The room of their fifth-floor Central Park West apartment at 72nd Street is at eye-level with the parade’s gigantic balloons.

In the library, which separates the sun-room and the living room, there is a 19th century Americana feel, where Ms. Mirviss and Mr. Levine hang their collection of American still-life paintings created between 1850 and 1920. Eight paintings hang over the couch. Two others — the couple’s best — are on loan to the Brooklyn Museum. Ms. Mirviss’s favorite painting, L.W. Prentice’s “Cherries on a Bough” (1895), remains in the library.

While the library has American décor and art, the paintings in the living room are more modern and abstract, complementing the contemporary, Asian design to the room. Two abstract collages done in the 1930s by Susie Frelinghuysen, who was married to Robert Morris of the Park Avenue painters, hang at one end of the room. On an adjacent wall hangs a painting by a local artist, Alvin Friedman, a postal worker in Queens who was discovered by art critic Clement Greenberg.

On the other wall is a large bookshelf separated by a fireplace, which is filled with ceramics and glassware made by European and Americans. Originally, Ms. Mirviss collected Japanese ceramics, but when she started dealing in 1984, she started to collect European and American pieces instead.

For Ms. Mirviss’s inaugural exhibition at her gallery, “Views from the Past, Visions of the Future: Masterworks of Japanese Art,” about 55 Japanese paintings, prints, and ceramics will be for sale.