Takasago stable
He was born Atushi Moriyasu in Nōgata, Fukuoka, the same city that "ōzeki" Kaiō came from, and they went to the same middle school. Moriyasu admired Kaiō greatly and when he joined professional sumo he deliberately avoided Kaiō's Tomozuna stable, hoping to one day face him in a tournament. He chose Takasago stable instead and made his first appearance at the March tournament of 1993, fighting under his family name of Moriyasu. He was just tall and weighed only in his debut tournament. In the lower divisions he served as a "tsukebito" or personal attendant to a number of senior wrestlers in Takasago stable such as Mitoizumi and Toki. In May 2001 he changed his "shikona" to Ōga, with the "ō" character taken from his idol Kaiō and second "ki" from Toki, which can also be read as "ga." He changed the second part of his "shikona" from Atsushi to Akitoshi at the same time. He was to change this again to Tosa and then finally Atsushi once more, his real given name.