Ōmagari was a city located in Akita Prefecture, Japan. The city was founded on May 3, 1954. On March 22, 2005, Ōmagari, along with the towns of Kamioka, Kyōwa, Nakasen, Nishisenboku, Ōta and Semboku; and the village of Nangai, merged to create the city of Daisen. Wikipedia