[1][2][3] During the Toyotomi era, Izumo was under the control of the Mōri clan, which ruled over nine provinces in the San'in and San'yō regions.

However, following the 1600 Battle of Sekigahara, the Mōri were reduced to the two provinces of Suō and Nagato, and the Kikkawa clan was transferred to Iwakuni Domain.

This marked the start of "Izumo Tomita Domain", as initially its stronghold renamed Gassan-Tomida Castle.

Tsuyama Domain even sent inspectors to examine the proposed new territories, but Mori Tadamasa died in Kyoto in 1634 and the discussion was abandoned.

For this reason, a monopoly was established from an early date on to control the production of wax, ginseng, cotton, and iron.

Fumai took advantage of the improvement in the domain's finances, to devote himself to the Japanese tea ceremony, which had been his hobby for some time, founding the Fumai-ryū school.

It had a kokudaka of 10,000 koku initially taken directly form the treasury of the parent domain, and thus did not have any physical estates until 1684 when the Mori jin'ya in what is now the city of Yasugi, Shimane was built.

It was also not subject to sankin kōtai, and its daimyō alway resided at the domain's mansion in the Kita-Aoyama area of Edo.

It had a kokudaka of 10,000 koku of new rice lands taken directly form the treasury of the parent domain, and thus did not have any physical estates.