The North Shore revels in Olympic gold of Kayla Harrison

By Matt Woolbright, Globe Correspondent

MARBLEHEAD -- To the world, Kayla Harrison embodies the fierce fighting technique and intimidating power on display Thursday when she dispatched the competition en route to America’s first Olympic gold in judo.

But here, on the North Shore, she’s the affable friend and mentor who’s planning to become a firefighter.

“She’s wise beyond her years, and an amazing fighter,” said Stephan O’Sullivan, a Marblehead woman who opened her home to Harrison last year. “But she’s also still a kid. She’s goofy.”

Harrison, a 22-year-old judo prodigy from Ohio, endured sexual abuse by a former coach before coming to train at Pedro’s Judo gym in Wakefield. It was there that the O’Sullivans met and befriended Harrison.

Four-and-a-half years later, they huddled around a family computer to watch the woman who had become part of their family win the sport’s highest honor at the London games.

“Knowing she was making history was just huge,” O’Sullivan said. “We all screamed when she won, and I was crying.”

Harrison moved in with the O’Sullivans a year-and-a-half ago, so Harrison didn’t have to live in the team house. Though Harrison moved out of the O’Sullivan house and into an apartment with her fiancé in February, she remains family to the O’Sullivans.

“When you see the TV shows, you always see the big sister watching the little sister,” said Darcy O’Sullivan, Stephan O’Sullivan’s 11-year-old daughter. “That’s how Kayla is with us. She’s always been there for us.”

Judo is a family pillar for the O’Sullivans. The girls are required to stick with the sport until they get their black belt. It’s what brought Harrison into their lives.

Part of the program at Pedro’s gym requires more experienced judo practitioners to mentor younger athletes.

O’Sullivan’s 13-year-old daughter, Kaelin, drew Harrison when she started judo classes more than four years ago.

“It’s really fun to spar with her -- she’s very entertaining,” Kaelin O’Sullivan said. “She’s obviously way better, but she teaches me and gives me pointers as we go.”

But the challenges aren’t just fun and games -- Kaelin O’Sullivan has her eyes on the 2016 games, and Harrison knows that.

“She doesn’t go too easy,” said Kaelin O’Sullivan, who has already amassed more than 70 accolades for her fighting.

“She will still sweep my legs and knock me on my butt just enough,” she said, with a chuckle.

Hana Carmichael has known Harrison since middle school in Ohio, when they competed on the Junior National Team. Now, they both train at Pedro’s in Wakefield, where nearly every day for the past several years, they have spent four hours together.

Harrison’s intensity and ability to rally her mind are what sets Harrison apart, Carmichael said.

“We all pull each other up, but Kayla is better mentally than all of us, easily,” Carmichael said.

When Harrison left for London, Carmichael said she already knew the outcome.

“I knew she was going to come home with the gold. It was simply a matter of how she would win, not if,” Carmichael said.

Even while preparing for her sport’s ultimate test, Harrison found time to play tag or hide-and-seek with Kaelin and Darcy O’Sullivan.

“She doesn’t just come over to come,” the girls’ mother said. “She plays with these girls, and she’s just a kid with them.”

After one of Darcy O’Sullivan’s particularly good hiding spots had bewildered Harrison long enough, Darcy decided to scare her “big sister.”

“She just walked by the closet I was in, and I opened up the door and said, ‘Are you still looking?’ ” Darcy O’Sullivan recalled. “Then, she screamed like a little girl.”

The bond between Harrison and the O’Sullivans transcends the courtesies typically extended to fellow athletes, Stephan O’Sullivan said.

“My husband feels like a second father to her -- he’s someone she can confide in and talk to,” she said.

Harrison’s relationship with Stephan O’Sullivan’s husband and her fiancé spurred another goal for when Harrison returns home.

She wants to become a firefighter like her “second dad” and her future husband.

It’s a goal Harrison will probably reach soon after her triumphant return, Marblehead Fire Chief Jason Gilliland said.

“She’s very quiet, humble, unassuming, and, obviously, very focused,” said Gilliland, who added that Harrison passed her emergency medical technician class with “flying colors.”

The Marblehead firehouse, where Harrison’s fiancé works, has been festooned with a banner supporting her quest for Olympic immortality for the past month: “Good luck Kayla Harrison. Bring home the gold!”

“It’s one thing watching [Michael] Phelps, but when it’s someone you know, that’s just amazing,” Gilliland said.

A Marblehead firefighter’s schedule -- work 24 hours, take a day off, then work another 24-hour shift before taking a five-day respite -- has proven especially appealing to Harrison, Stephan O’Sullivan said.

It means she can keep training.