• Mitoyo District was created by the merger of two separate districts, (三野郡)
Mino-gun and (豊田郡)
Toyota-gun in 1899. • On October 11, 2005 - the towns of
Ōnohara and
Toyohama merged to form the city of
Kan'onji. • On January 1, 2006 - the towns of
Mino,
Nio,
Saita,
Takase,
Takuma,
Toyonaka and
Yamamoto were merged to create the city of
Mitoyo. Mitoyo District was dissolved as a result of this merger. (Merger Information Page in Japanese)