After supporting roles in “The Office” and “Bridesmaids,” Ellie Kemper has broken out on her own as the title character in “Unbreakable Kimmy Schmidt,” a relentlessly upbeat young woman rebuilding her life after 15 years in a bunker.

Created by Tina Fey and Robert Carlock, the antic comedy returns to Netflix for a third season Friday and finds Kimmy enrolling in college and divorcing the Rev. Richard Wayne Gary Wayne (Jon Hamm), the cult leader who held her captive.

Raised in a family of four kids from St. Louis, Kemper is modest and cheerful — Midwestern to the core. During a recent conversation at 30 Rockefeller Plaza, the 37-year-old Emmy nominee talked about her childhood, her years in the showbiz trenches and life in the limelight.

The building holds a lot of warm memories for Kemper, who got a big professional break as an intern on “Late Night With Conan O’Brien,” where she also met her future husband, writer Michael Koman. Last year, the couple welcomed a son, James.

Last season Kimmy went to therapy and reconciled with her mother. What challenges await this season?

Kimmy's a real fixer upper. She really believes that she can change people. Her challenge in life going forward is that there are circumstances that are beyond her control. She wants to escape her past, but it's always going to be with her and she has to grapple with it. Something like that can't be buried. Kimmy has this innate optimism and brightness, but she also has this tenacity and strength which enabled her to survive in the bunker. There's a lot more to her than her sunny exterior.

Even the colors she wears now are different — a little more "autumn."

The first season I was like, this character would stick out like if she went to the cafe. And now she's almost, I don't want to say fashionable, but she's coming of age in her wardrobe choices, which I think reflects her coming of age, because she missed adolescence. She's maturing.

The show is so funny, but it also has a powerful message that seems to resonate with people.

There have been many people who mentioned that it helped them get through some horrible news, a sickness, breakup, death of a family member -- really difficult things. It makes me proud of our show. It is this combination of a bright, funny, very sharply written comedy but the whole premise is so dark and traumatic. At the core is this survival story.

Fudge yes we can! "Unbreakable Kimmy Schmidt" - Season 3

Your sister, Carrie Kemper, is a comedy writer. Were you both into pop culture growing up?

No, it's alarming. My husband, who was a comedy nerd growing up and has seen and heard everything, is constantly just amazed at the things I haven't seen. It's weird because I feel a similarity to Kimmy in that way. I had a very privileged, nice, warm childhood. She did not. But the pop culture from that time did not seep into my veins. I always tell my husband it's because I had friends. I wasn't holed up in my room watching TV. I don't know where my sister and I were while things were happening. Maybe it's because we were putting on plays. I hope I'm not blocking anything.

Tell me about learning improv from Jon Hamm

Jon Hamm went to the same high school as I did and he came back and taught the improv portion of my ninth grade acting class for a year. He was the first person to introduce this notion of "yes, and." Now I sound like an improv dork, but it's like the very crux of improv. You take what your scene partner gives you and you never deny or negate it. It's a simple but profound concept because it's how you navigate life. It's such a handy tool.

You went to Princeton. Where are you on the preppy spectrum?

Not on it. I feel like when I first moved out of the Midwest, that's when I became aware of how Midwestern I was. It was really at college that I was struck by the fact that not everyone says hi to each other or smile at each other and I thought that people were so rude. I was homesick the first year and then I also played field hockey, which was not the best fit. I think I played a combined 2 minutes and 18 seconds. But I actually love the preppy aesthetic. I wish that I could nail it. We were going to a welcome-back barbecue senior year and I was wearing like a 3/4-length shirt and these teal shorts. I remember asking my roommate, "Is this too fancy for a barbecue?"

Did you have to take a lousy day job when you moved to New York after graduation?

I signed up for improv classes and did these temp day jobs during the day. There would be afternoons where I wasn't working and I was at home. I remember my roommate and I were both home one afternoon and we were eating grilled cheese sandwiches with Cheetos and carrots. And we looked down and we were like, this is an all-orange meal. It's the middle of a weekday. We're 24. What is our life? It just felt so pathetic.

I also typed for a writer for Vanity Fair for a couple of weeks. He would dictate and I would type. I never saw the article I was writing. It was about Whitney Houston. It was very weird. Now that I'm describing it, it sounds like "Mad Men." I think the longest job I had was at Crumbs, the cupcake shop.

Did you and your former boss, Conan O'Brien , bond as redheads?

I always feel a bond with redheads. It's not even red. It's orange. It's like polite of everyone to say it's red, but it's orange. Conan's always made jokes about how pale he is, but we have the palest son on the planet and so far he has red hair. We're like, Conan lives on in our son! [Pause] But Michael is the father, just to be clear.

I feel like I have to ask if you were into "Anne of Green Gables."

Actually the thing I read growing up was "The Baby-Sitters Club." That was my favorite. And I remember my mom was like, you should try to broaden your horizons. I think she suggested "Little House on the Prairie." I went to Waldenbooks — remember that? — and bought "Sweet Valley Twins."

You’ve written for places like the Onion and McSweeney's. Is that something you want to return to?

I am writing a book of humor essays, and I say that with my tail between my legs because I need to return to writing it. It's always easier to talk about writing your book than it is to sit down and do it.

You also wrote a piece for the New York Times about bombing on your first visit to "The Tonight Show” and crying in the darkness while musical guest Jakob Dylan performed.

Yes. It went so horribly wrong. I was so amped up for it and worried and all these different emotions and I felt like I had embarrassed myself and I didn't know if [lead guest] Garry Shandling was making fun of me. It was just an awful experience. I don't know if you've heard the song, ["Nothing But the Whole Wide World"] but it's really sad. Being on a live television show can be a nerve-wracking experience when you're the guest. I remember going home and telling everyone "Don't watch."

But since then you've become a talk show pro. You guest-hosted "The Ellen DeGeneres Show" and "Today."

It's nicer when you're the one who's in charge. I still get nervous every time I'm a guest.

What are you watching these days?

My favorite show is "The Mindy Project." It strikes the best balance between comedy and drama. It takes me out of my own head. I feel like the show is so singularly her and there's no show like it. I think Mindy is so funny.

meredith.blake@latimes.com