In a land area of 27,051 square kilometers, the diocesan territory covers Kanagawa, Shizuoka, Nagano and Yamanashi prefectures.
In the diocesan territory, the population is 15,621,976 at end of 2008. (The population of the whole country is 127 million). Most residents are ethnic Japanese. There are also 335,289 non-Japanese people, according to the Immigration Bureau of Japan as of 2008.
The territory also has many languages/dialects.
The Diocese of Yokohama was established on Nov. 9, 1937, when the Archdiocese of Tokyo was given over to the care of Japanese clergy, and the eight prefectures of Kanagawa, Shizuoka, Yamanashi, Nagano, Saitama, Gumma, Tochigi, and Ibaraki were entrusted to the Paris Foreign Mission Society. On Nov. 9, 1939, the Prefecture Apostolic of Urawa was established and the four Prefectures of Saitama, Gumma, Tochigi, and Ibaraki were entrusted to Canadian Franciscans.
At the time of the establishment of the Diocese of Yokohama, Archbishop Jean-Baptiste-Alexis Chambon, M.E.P., who had been Archbishop of Tokyo, served as the first ordinary. When he retired in 1941, Monsignor Miyoichi Ideguchi, and then, from 1944, Monsignor Tatewaki Toda served as Administrator Apostolic of the Diocese of Yokohama. With the death of Monsignor Toda, Archbishop Doi of Tokyo served temporarily at the same time as ordinary of the Diocese of Yokohama. However, in 1947 Father Asagoro Wakita was consecrated and took over as Bishop of Yokohama. In 1951 Bishop Wakita resigned, and Father Katsusaburo Arai was appointed Bishop of Yokohama. He was consecrated bishop on Feb. 24, 1952, and retired in 1979.
On Oct. 30, 1979, Bishop Fumio Hamao, Auxiliary Bishop of Tokyo, was appointed Bishop of Yokohama. He was installed on Jan. 15, 1980.
On June 15, 1998, Pope John Paul II nominated Bishop Hamao as President of the Pontifical Council for the Pastoral Care of Migrants and Itinerant Peoples at the Vatican. With this appointment, effective June 15, 1998, Bishop Hamao became an archbishop and relinquished the office of Bishop of Yokohama. He was succeeded by Father Masahiro Umemura, who was appointed March 16, 1999, and was ordained bishop on May 15 that year. (Catholic Bishops' Conference of Japan, 2010)
The cited information not mentioning the source is by Catholic Bishops' Conference of Japan, as well as the photograph/s of the officials. Photograph/s of the cathedral is by the Diocese.
Air planes, railways, ships and buses are in use in the diocesan territory.
The Ministry of Internal Affairs and Communications reported as of 2005, that per capita income in the diocese territory is in:
Kanagawa: 3,204,000 JPY/year (USD35,607 as of February 2010)
Shizuoka: 3,344,000 JPY/year (USD37,166 as of February 2010)
Nagano: 2,838,000 JPY/year (USD31,558 as of February 2010)
Yamanashi: 2,729,000 JPY/year (USD30,347 as of February 2010)
Major industries are in:
Kanagawa: Electric equipment, transport equipment, general equipment, chemicals and petroleum products
Shizuoka: Transportation equipment and machinery, musical instruments, electrical machinery, chemical engineering, food products
Nagano: Electrical and electronics, information, machinery, food products, tourism products, tourism
Yamanashi: General machinery, electronic components, electrical machinery, food products, information and communication machinery
(Japan External Trade Organization, 2010)
Throughout Japan, literacy is 99 percent, according to Central Intelligence Agency, USA, in 2010.