千葉氏
The Chiba clan, or branches of it, ruled the Shimōsa region for about 400 years from the Kamakura period. During the Sengoku period, the Chiba clan gained the protection of such powerful clans as the Odawara Hōjō clan, allowing them to get a stronger foothold over the area. They lost control when the Hōjō clan was overthrown in 1590 by Toyotomi Hideyoshi. After that, General Kiso Yoshimasa settled in the region. He restored the Ajito Castle, which was the inspiration for the name "Asahi." When poet Nonoguchi Takamasa visited the area in 1852, he wrote a poem about the general, from which the name "Asahi," which can mean "rising sun," was taken: