Seppun Osuki was a shugenja of the Imperial Families. She was the youngest of three sisters. When the eldest, Seppun Osokawa, was appointed as administrator of the Hundred Stances Dojo, she took Osuki and her other sister, Seppun Osoko, with her. Osuki was outgoing and emotionally fickle, being openly courted by several samurai at the dojo.