In a land area of 44,842 square kilometers, the diocesan territory covers Aomori, Iwate, Miyagi and Fukushima prefectures.
In Sendai diocese, the population is 7,207,624 at end of 2008. (The population of the whole country is 127 million). Most residents are ethnic Japanese. There are also 41,192 non-Japanese people in 2008, according to the Immigration Bureau of Japan.
The territory also has many languages/dialects, including Kesen-go, in which the Gospels are translated.
The Diocese of Hakodate was separated from the Northern Vicariate Apostolic of Japan on April 7, 1891, and included Hokkaido (later also Sakhalin) and the seven prefectures of Aomori, Iwate, Miyagi, Fukushima, Niigata, Yamagata, and Akita. It was entrusted to the Paris Foreign Mission Society and Bishop Alexandre Berlioz was appointed the first ordinary.
Later, with the establishment of the Prefecture Apostolic of Niigata on Aug. 13, 1912, the three prefectures of Niigata, Yamagata, and Akita were entrusted to the Society of the Divine Word. On Feb. 12, 1915, when the Prefecture Apostolic of Sapporo, including all of Hokkaido except the district of Hakodate, was established and entrusted to the Fulda (Germany) Province of the Order of Friars Minor, the area of jurisdiction of the Hakodate Diocese was reduced. On the retirement of Bishop Berlioz, Monsignor Alfred Joseph Wood served for four years as interim ordinary for the Hakodate Diocese. In November 1931 the Hakodate Diocese was entrusted to Canadian Dominicans. Following Monsignor Wood's four years of service, Bishop Andre Dumas, O.P. served as ordinary.
In 1936 Father Marie-Joseph Lemieux, O.P. was appointed to succeed Bishop Dumas. On March 9, he received permission from the Holy See to move the center of the Diocese from Hakodate to Sendai and to change the name of the diocese from the Diocese of Hakodate to the Diocese of Sendai. Later, on June 29, 1936, his episcopal consecration was held. In 1941 Bishop Lemieux resigned and Father Wasaburo Urakawa, a specialist in Japanese Christian history, was chosen to succeed him and was consecrated bishop. In December 1952, the district of Hakodate was separated from the Diocese of Sendai and was incorporated into the Diocese of Sapporo. With this, the area of jurisdiction of the Diocese of Sendai became the four prefectures of Aomori, Iwate, Miyagi, and Fukushima.
In 1954 Bishop Urakawa resigned and Father Arikata Kobayashi was consecrated bishop to succeed him and served as Bishop of Sendai for 22 years. In 1976 Bishop Kobayashi resigned. Father Chihiro Sato, O.P. was appointed to succeed him and was consecrated bishop on March 20. He resigned on June 19, 1998.
After two years' vacancy, Salesian Father Osamu Mizobe was named as the successor of the See on June 12, 2000. He was consecrated Bishop on Sept. 9, 2000.
May 14, 2004, Pope John Paul II appointed Bishop Osamu Mizobe, S.D.B. as Bishop of Takamatsu, he was installed Bishop on July 19, 2004. Therefore, the place of Bishop of Sendai was vacant about one and a half year.
On Dec. 10, 2005, Msgr. Tetsuo Hiraga, was appointed Bishop of Sendai, and consecrated on March 4, 2006. (Catholic Bishops' Conference of Japan, 2010)
The diocesan territory is well connected by air planes, railways and buses.
According to the Ministry of Internal Affairs and Communications, the per capita income (2005) was in Aomori JPY2,184,000/year (USD24,100), in Iwate JPY2,363,000/year (USD26,072), in Miyagi JPY2,620,000/year (USD28,912) and in Fukushima JPY2,728,000/year (USD30,090, all currency rates as of February 2010).
Major industries are in: