Otose お登勢 is actually the 源氏名 genji na or 'professional name' used by geishas and hostesses, her real name is Terada Ayano 寺田 綾乃. She holds the title of one of the 4 Devas of Kabuki District かぶき町四天王 kabuki chou shitennou and runs Otose's Snack House in the 1st floor below the Yorozuya. She oftens visits the Yorozuya, or sends one of her employees, Tama or Catherine, to collect rent.
She wears a dark brown/black kimono and has brown hair. Known to be a beauty in the past, the Yorozuya couldn't believe it when they found out her real identity, as she was the first love of a dying old man who wanted to see her again.
She is forgiving and cares for her employees, as seen with Catherine. However, she is very strict and demands rent from the Yorozuya every month. In case they don't pay, she has been known to either employ them to clean her bar or sending Tama, later equipped with a weapon system, to collect it from them.
She views Gintoki, Shinpachi, Kagura, Catherine and Tama as family.
Otose is a widow whose husband, Terada Tatsugorou, died in a past war. She grew up with Doromizu Jirochou 泥水 次郎長, and would always keep him out of trouble. However, after Tatsugorou died, Jirochou would leave his own family to come back and protect the town, and Otose.
One day, when visiting her husband's grave, Otose would meet a younger Gintoki. In exchange for food she had brought as offerings for her deceased husband, Gintoki vowed that he would never forget this debt, and that he would watch over her. 
- In Episode 43 of the Gintama anime, Otose slithers her tongue as Sarutobi Ayame stated that she is not a woman at all, or maybe Orochimaru was inside of the old hag (because her voice actor is also the voice actor for Orochimaru in Naruto).