“People can sense my energy,” says Kirby Griffin, almost laughing at herself. “I’m super chill.” The millennial archetype of “the cool girl”—somehow impossibly hot and totally indifferent to said hotness—may be a myth, but our September Playmate is something of a unicorn. Kirby is next-level gorgeous (a young Tyra Banks comes to mind), but with her up-for-anything attitude, she’s also thoroughly unpretentious. “I’m just a nice girl,” she says. “That’s my mama’s doing. She encouraged me to talk to people, especially shy people, from a really young age. I didn’t wait for them to come to me.” Kirby’s small-town upbringing, in the southern Georgia city of Americus, also plays a part. “I had the best childhood ever,” she says. “Of course you’re exposed to more when you’re from a city like L.A. or New York, but I grew up around acres of peach trees, riding bicycles with my girlfriends and go-karts with the boys.” When she was 13 years old, she and her family, including four younger siblings, relocated to Wisconsin—an exercise in culture shock that she came to appreciate. “It exposed me to other things and broadened my perspective. Now I welcome change with open arms.” Kirby attended the University of Wisconsin for about a year and a half before being discovered by a model agent while celebrating spring break in Miami’s South Beach. Her career took off; by 2012 she was in Zambia, shooting for Sports Illustrated.