What is yuka doll?

As an AI language model, I am not sure which specific Yuka doll you are referring to as there are various types of dolls with the name Yuka. However, Yuka could refer to a popular Japanese fashion doll brand produced by Takara Tomy. These dolls feature a unique body proportion and are known for their fashionable clothing and accessories. Some Yuka dolls are also interactive and can speak phrases in Japanese. They have become popular among collectors and fans of Japanese culture.