Paris Hilton and Brooke Mueller
John Milne/Startraks; John Shearer/Wireimage
04/17/2011 at 01:00 PM EDT
No stranger to eyebrow-raising scenarios, it only makes sense that Paris Hilton
calls her new Oxygen series "very dramatic."
But it's not just Hilton who brings intensity to the small-screen in her latest reality TV venture. The socialite says when her show premieres June 1, viewers will see "everything" unfold with her tabloid-friendly pal and costar Brooke Mueller, who has been fighting addiction publicly while battling her ex
, Charlie Sheen
"Brooke's an open book," Hilton, 30, told PEOPLE on Friday, while promoting The World According to Paris
at NBCUniversal Summer Press Day at the Langham Hotel in Pasadena, Calif. "She's not afraid to show who she is. She's not afraid to tell the truth. And as a producer of the show, I love that for TV. I love someone who's not afraid to show everything."
Hilton and her mom Kathy continue to stand by Mueller, 33, even when the cameras aren't rolling.
"What she's going through is a daily struggle," Kathy notes. "It's a work in progress."
Adds Paris, "We've been friends for years. My mom and her are very close, and she's one of my good friends as well."
And luckily Paris's close ties with Sheen, a neighbor, don't impact her relationship with Mueller.
"Brooke doesn't mind that we're friends," Paris says. "She knows that I met him before I met her."