Kylie Jenner - Kendall And Kylie Jenner Writing Book

Kris and Bruce Jenner's daughters are collaborating with co-writer Maya Sloane for their debut book, a sci-fi story about two sisters set 200 years in the future.

The as-yet-untitled tome is due to hit shelves next summer (13), and Kylie, 14, and Kendall, 16, hope it will be the first in a series.

Kendall tells E! Online, "We want to do something so different, something that we really love," and Kylie adds, "I think we will definitely get it done (soon) with how fast (the process) is going."