Dōtanuki (同田貫) is a name of a Japanese school of sword smiths from Higo province who produced swords in the Bizen tradition during the feudal period of Japan.
The Dotanuki school evolved in Higo Province with its ancestry going back to the famous "Enju Kunimura". Enju Kunimura founded the Higo Enju school in approximately 1305. Kunimura was born in Yamato province to the swordsmith Hiromura. He moved to Yamashiro province, became a student of Rai Kuniyuki, and later married Kuniyuki's daughter. Kunimura then moved to Higo and founded the Enju school. There are only six blades by Kunimura known to exist.
The Dotanuki school emerged in the small Higo village of Dotanuki in the mid-16th century, following the decline of the Higo Enju school in the latter part of the Koto period. The Dotanuki school founder is said to be Dotanuki Masakuni, he was called Oyama Kozuke no Suke and his original signature was Nobuyoshi. The famous general Katō Kiyomasa honored Masakuni with one character of his name, and from that point onward Nobuyoshi was known as Masakuni. However, the majority of his works are only signed "Dotanuki Kozuke no Suke".
Dotanuki swords quickly gained great popularity among the warrior class due to their superior cutting ability. The Dotanuki smiths cared little for aesthetics, but instead focused on strength, sharpness, and durability in the field. They were renowned for producing blades which would endure the harshest conditions, the most difficult battle field situations and survive to return to battle day after day, year after year.
One of the most feared, respected and ruthless of Hideyoshi's Generals was Katō Kiyomasa. General Katō was known as a ferocious and ruthless fighter, a true warrior. So intense was General Katō that he was called "Kishokan" or "Devil General". When Hideyoshi sent General Katō to lead the invasion of Korea, the General chose Dotanuki smiths to accompany him to ensure adequate swords could be produced in the field.