"Cute" only goes so far in the entertainment business.

There was certainly a huge "cute" factor in play when Bruno Mars, then known simply as Bruno, first hit national awareness as "the world’s youngest Elvis" in the late ’80s, but "cute" didn’t get him to the top of the Billboard Hot 100 or earn him seven Grammy nominations as a songwriter, record producer and recording artist at age 25.

Hawaii is where it all began for Bruno Mars, born Peter Gene Hernandez. As friends and family look back at those early days, they agree he had the work ethic of an entertainer many years his senior.

Tommy D, a longtime Waikiki entertainer who worked with Mars a decade ago in "Aloha Las Vegas," a celebrity impersonator show in Waikiki, remembers him as "one of the most incredible talents I’ve ever seen."

"He was always on time, he always showed up, he knew his show, he knew what he had to do … and he could sing, he could dance and he could play five instruments," he said.

The youngster "was always surrounded by music," says Mars’ uncle John Valentine. "At every family gathering all of us would be singing, and he would be the biggest ham."

None of Mars’ five siblings could match his charisma, according to his mother, Bernadette "Bernie" Hernandez, a former professional singer. "All my kids sing but they’re shy. You put them on stage and they choke, but Bruno wanted to be on stage," she said.

The prodigy never took music or voice lessons. "He just picks up an instrument and figures it out," Hernandez said in a phone interview from Los Angeles, where the Grammys are being held today.

While still in diapers, a young Bruno was already rehearsing his "act" for company.

"He was a natural. At age 2 he would lock himself in the room and do his thing over and over and over. He would come out and he would show us," she said. "When people would come over, he would point to himself, (as if to say) ‘Introduce me, introduce me.’

"Picture a 2-year-old. Even if he couldn’t pronounce the words, he would sing the beat and he was on pitch," his mother said.

The toddler also couldn’t get enough of ’50’s-era "doo-wop" music or Elvis Presley, apparently. Even at that early age he knew enough to operate a VCR and fast-forward videos to the Elvis numbers.

Mars’ father, Pete "Dr. Doo-Wop" Hernandez, recalls getting up in the middle of the night and finding his son in the living room watching videos and practicing his moves.

"If there was a particular scene in an Elvis movie or an Elvis concert, he would watch it over and over and practice and practice imitating the moves. He could never get enough practice time," he said.

"LITTLE ELVIS" got his first break a couple years later while his father’s doo-wop revival group, the Love Notes, was in Japan for the opening of a Sheraton hotel.

"And the amazing thing was, it was something he wanted. He always wanted to come on stage," Pete Hernandez said. "He finally convinced me in Japan. I pulled him up on stage, and he starting shaking his legs and the people went wild. I knew the novelty value was just phenomenal."

Then around that same time, his mother made him an Elvis outfit for Halloween, and the family went out to Waikiki. Mars drew a big crowd when he started singing. "Everybody was throwing money. He made $100 in 20 minutes," Bernie Hernandez said. "The applause he got!"

The local television show "Hawaiian Moving Company" happened to be in Waikiki that night and asked to film Mars at the Sheraton, where the Love Notes were booked in the Esprit Lounge. After the show aired, the phone wouldn’t stop ringing, she said, and Mars became part of the act.

"From that night, he worked every night at age 4," she said, adding that her son picked his own songs "because you can’t force a kid to do something he doesn’t want to do."

The publicity surrounding "Little Elvis" sparked concerns of child exploitation, and the Hernandezes had to appear in Family Court to prove their son was not being forced to perform. The judge asked to see a little bit of his act.

"He was tiny, so I put him on the table," Bernie Hernandez said. "He was so funny and he was so cute."

He wowed the judge and it was "case closed." At 6 he appeared as an Elvis impersonator in the Nicolas Cage movie "Honeymoon in Vegas."

Later, while a student at Roosevelt High School, Mars directed a school play, put together a Love Notes spinoff group with three classmates and choreographed pep rallies. "He never lost his focus on what he wanted to do — never got into sports — all the way through high school," Bernie Hernandez said.

His father credits Mars’ personality with getting him through school. "I’d rarely see him carrying books, but he always had a guitar or a ukulele or something. It became like an inside family joke," he said.

After graduating, Mars moved to Los Angeles to pursue his career.

WHEN IT CAME to his music, Mars did not shy away from hard work, even as a youngster.

Valentine recalls an early recording session. "We spent three or four hours in my studio ’cause he didn’t read. He was only 5. So I had to feed him every line, and he would memorize the words and sing the line. Then I told him we had to go back and fix up all the flat notes and the wrong notes — that’s where he got that training."

Valentine adds that Mars maintains that work ethic today.

"I was with him for three days in L.A. recently, and he is a fanatic in the studio. … The whole time I was there, we didn’t do anything (social) — we just worked! He said, ‘That’s why I’m here. This is all I do. I just work my ass off.’"

As for the elder Hernandez, opening for his son at Blaisdell Arena in December was the thrill of a lifetime.

"I was blown away by him — truly in awe. His professionalism was so polished and so sharp. As much as I love performing, I felt that if I never did another show in my life, I would be content," he said.

Mars’ Honolulu concert capped a breakout year for the entertainer. Just last April he was performing at Level 4 at the Royal Hawaiian Center, where the top ticket price was $25.

Mars blew up as an "overnight success" after his guest vocals on international pop hits by B.o.B. ("Nothin’ on You") and Travie McCoy ("Billionaire"). His first full-length album, "Doo-Wops & Hooligans," peaked at No. 3 on the Billboard 200, and the first single from the album, "Just the Way You Are," topped the Billboard Hot 100 singles chart.

By the end of 2010, Mars had garnered seven Grammy nominations and was in the middle of a sold-out concert tour. He’s among a glittering list of performers appearing at tonight’s 53rd Annual Grammy Awards ceremony.

The only blot on an otherwise perfect year was his arrest in September for possession of a small amount of cocaine. Mars will be given a chance to put the incident behind him at a Las Vegas court hearing tomorrow to finalize a plea agreement that would expunge the arrest from his record if he stays out of trouble for a year.

Star-Advertiser writer Leila Fujimori contributed to this report.