Chubei Ⅰ established his first store in Honmachi, Osaka in 1872. Yae took charge and led the entire operations of Toyosato Honke. Her responsibilities then grew to significantly exceed the traditional role of a merchant's wife.

Yae selected the rice and tobacco that were used in the Osaka store, made fermented soybean paste and pickled plums, repaired futon mattresses, and purchased clothes and shoes for the store employees. Although these supporting duties must have already required significant work and attention, her active role did not end there. As an assistant of Chubei Ⅰ, she alone took charge of purchasing Ohmi linen in Goushu (now Shiga Prefecture). She handled a large volume of linen on a daily basis and gave orders to the carriers who gathered there to load linen from 3 a.m., and even prepared the employees' lunch boxes. Yae apparently did all this by herself, without asking anyone else for assistance.

Another of Yae's important responsibilities was to provide training to new store employees. In those days, when store employees were recruited to the Itoh family's stores as trainees, they would first be sent to Toyosato Honke where they received the education necessary for store employees from Yae, including lessons in manners and abacus. If store employees caused any problems at a later date, they were sent back to Honke to receive further training. Through this training process, Yae judged the characters and abilities of the individual trainees and thought about positions that would suit their abilities and aptitudes. Yae then suggested her observations to Chubei Ⅰ. Since these activities took place in Toyosato Honke, it can be regarded as the pioneer of today's employee training centers. In her old age, Yae said that she had brought up a lot of children.