Nostalgia has an essential appeal, especially when it both tugs at the heartstrings of memory yet also seems fresh and lively at the same time.

That’s what music lovers will get from Pure Heart, a trio that captured the hearts of Hawaii residents with its eponymous debut album in 1998. The album went on to sweep major categories in the following year’s Na Hoku Hanohano Awards.

The band, which was noted for the virtuosic ukulele playing of Jake Shimabukuro, the innovative percussion techniques of Lopaka Colon and the sensitive vocals of Jon Yamasato, plays Saturday at Hawaii Theatre in a concert with Anuhea and Justin Young.

This concert will provide the first opportunity since the band’s heyday for fans to enjoy Pure Heart’s full repertoire of love songs, traditional Hawaiian tunes, surfer tunes and instrumental showpieces.

“This is the first time we’re doing a full set, like how we did before,” Shimabukuro said. “So we’re incorporating all the songs from our two records.

“We’ve come up with some new arrangements, but we’re just trying to keep it very true to the original, like how we used to do things, and not drift too far. There are some sections where we’ll kind of let loose and have some fun.”

The group first reunited two years ago for a performance organized by Shimabukuro and has since played briefly on various occasions when the members’ schedules allowed. Some appearances have been widely publicized, such as their recent appearance at the Hoku Awards ceremony, but others have been private, almost impromptu affairs, such as when Shimabukuro recently invited Yamasato to a relative’s wedding.

“We got to play at the wedding, so it was a good rehearsal for us,” he said.

They’ll have had just a few formal rehearsals leading up to this performance, but all their songs have been coming back to them easily. That comes from all the time spent playing together in their early years, learning and gaining inspiration from each other.

“Lopaka, Jon and myself, we all have such different backgrounds musically,” said Shimabukuro, who remembers essentially “living” at Yamasato’s house at the time. “We all grew up listening to different things, and we all had different strengths, so we’d just bring different things to the table. It was like, ‘Wow, that’s cool, so let’s try this.’ And that seems to be happening again, 15 years later.”

Yamasato, who works in real estate and produces the music show “HiSessions,” which produces high-quality video for groups to post online or use on television, recalls that “time just flew by” during those sessions, which were “so much fun that they didn’t seem like practice at all.”

Their debut album “Pure Heart” won Hoku Awards for Album of the Year, Most Promising Artist, Contemporary, and Favorite Entertainer in 1999. “Pure Heart 2” repeated in the Contemporary category in 2000. But despite all those awards, band members weren’t sure of the impact they were having on the local music scene.

“I did not have that sense until maybe three years ago,” Yamasato said. “I always thought it was ‘just another trio.’ I didn’t think it was anything special, but when I started doing the ‘HiSessions’ show and people kept coming on — it’s all younger people now — and they’re saying, ‘When I was young, I saw you guys on TV and wanted to play the ukulele.’ That’s when I began to think we should play a little bit more. I didn’t realize how many people dug this stuff and wanted to play because of it.”

Yamasato, who considers himself the rhythm section as well as lead vocalist, marvels at the talents of his bandmates, noting how Colon, a music major in college, can easily respond when Shimabukuro suggests a change in tempo or pulse.

“Even if it’s something we’ve played 15 or 100 times, there’s this new element that makes it interesting,” Yamasato said. “And the audience responds to that.”

Yamasato also remembers the feeling of regret after it was decided that the band would break up.

“I do remember standing there at one of our last gigs thinking, ‘I will never find another ukulele player who can play like this. There will never be another yin to my yang, the way Jake and I fit.’”

Shimabukuro, of course, has become an internationally recognized star in the intervening years. He’s on tour constantly, created several solo albums, and is now involved in a business venture with his brother Bruce to produce an inexpensive, easy-to-play “entry-level” uke (with the blessing of the Kamaka family, the maker of his personal instruments).

He’s also putting the finishing touches on a new album, due out early next year, consisting of originals as well as covers of some oldies, like the Zombies’ “Time of the Season” and the Beatles’ “Eleanor Rigby.”

“I incorporated a lot of instrumentation,” he said. “We added strings, and horns, piano, guitars. … There’s this classical mallet player, Alan Spencer, who plays marimba and vibes. … We were able to bring in a lot of different colors, different instrumentation. We even covered a Jimi Hendrix tune (‘If 6 Was 9’).”

Save for one song that he performed with Bruce, Shimabukuro did not play Pure Heart tunes during the group’s hiatus, even as his solo career took off.

“It didn’t feel right playing those tunes without Jon and Lopaka,” he said.

Now, with those songs having lasting appeal, it’s especially gratifying to him to hear younger musicians playing the tunes Pure Heart popularized.

“There are songs like ‘Bodysurfing’ or ‘Wipeout’ or ‘Tokada.’ It’s nice that we get to revisit these old songs, but what’s cool is hearing a lot of the younger kids play all these songs,” he said. “I remember when I was playing these tunes, it was really challenging, but now you got kids that can play these tunes with no problem. The younger generation, they’re just so advanced.”

Shimabukuro remembers his own experience getting inspiration when he was in high school visiting his grandmother on Molokai. He and Bruce were jamming in the airport, playing “Kawika” by the Ka‘au Crater Boys, and then he saw “this big guy kind of walk close to us, listening, and then I realized that was Troy Fernandez of the Ka‘au Crater Boys,” he said. “I got so nervous!”

“He listened to us and afterwards he came up to us and said, ‘Hey, you guys sound pretty good.’ I got to talk with him and shake his hand. I’ll never forgot how inspired that made me.”