You can use yellow kimono for the usual outfit and prompt ponytail if you want that hairstyle
Important: 99% of the images for Kikunojo are labelled as "1boy" or "male focus" from most sources. Since Okiku prefers to look like a woman, you will likely need to prompt 1girl or female focus rather than 1boy or male focus or the model will give you a very masculine body with a feminine face