Yoruichi Shihōin (四楓院 夜一, Shihōin Yoruichi) is the former captain of the 2nd Division of the Gotei 13, as well as the former commander of the Onmitsukidō. Her Lieutenant was Marenoshin Ōmaeda. Having abandoned her command of both positions, she works with Kisuke Urahara and Tessai Tsukabishi, based in the Urahara Shop out in the Human World.
Yoruichi Shihōin was born the princess of the Tenshiheisōban (天賜兵装番, House of Godly Gears), the Shihōin Clan, one of the four noble families. Yoruichi grew up at the Shihōin Mansion in the Seireitei of Soul Society with her childhood friends Kisuke Urahara and Tessai Tsukabishi. During this time, they played together daily under the Sōkyoku hill training space, which Urahara built when they were children.
Later, Yoruichi became the Corps Commander of the Executive Militia of the Onmitsukidō while serving as the 22nd generational Head of the Shihōin Clan, becoming the first woman to ever hold the position.Some time later, she would serve as Commander-in-Chief of the Onmitsukidō, as the position is traditionally held by the heads of the Shihōin Clan. She eventually rose to the position of captain of the 2nd Division of the Gotei 13, further uniting the formerly separate military arms together, as this was also traditionally done by her family.
Some time later, she decided to change her role in the Onmitsukidō from being the Corps Commander of the Executive Militia, which is the position traditionally held by the Commander-in-Chief, to being the Corps Commander of the Corrections Corps. While Yoruichi was Onmitsukidō Commander, she took in Suì-Fēng as a personal bodyguard. Recognizing her talent, she became a mentor and friend. She taught Suì-Fēng most of the techniques she knew. During her time in Soul Society, she created many techniques which involved Shunpo, and taught some of them to Byakuya.