PORTSMOUTH ó The longtime burger joint on Bow Street affectionately known as Fat Belly's will close in mid-January and later reopen as an Asian fusion kitchen.

Much of the reason, according to owner Joe Kelley, is "we're not really making money selling hamburgers for $12 anymore, and paying downtown rent." After 14 years, Kelley said, "It's just time to start clean."

"For me as a business owner, Iíve tried to keep up with the times, and it's incredibly hard when the place has been one thing for so long," he said. "If you go to 90 percent of the restaurants in town, they have the same menu; American bar and grill food."

Fat Belly's has been known for its "build your own burger menu" and a small upstairs dance floor that attracts late night crowds. The new restaurant will still maintain many of Fat Belly's features, but sport a new, more "fine" approach.

The concept will be named Fuki, an Asian fusion kitchen with cocktails and nightlife.

Kelley, who also owns the Thirsty Moose restaurants and Joe's New York Pizza, called it "Asian comfort food, super approachable." He expects Fuki will open in February.

They won't do much to the existing space other than a facelift, Kelley said, but much of the staff will be new.

"I donít think thereís anything comparable to it right now," Kelley said. "I think itís something downtown doesnít have. I think itís just different enough that it will keep us there for another 14 years."

Executive chef and partner Zack Squier is a hometown boy who grew up working in many Portsmouth restaurants. His latest venture was opening Umami, a restaurant in Northwood. He has since moved on from there, and pitched Kelley the idea of Asian fusion in downtown Portsmouth.

"Everyone is really upset Fat Belly's is leaving, but weíre still going to have a lot of that, itís just going to be a bit more fine dining," Squier said. He noted they'll continue the nightlife aspect, with DJs every weekend. They'll also turn up the volume on the cocktail program, which will be headed up by new general manager Kyle Chauncey.

Squier said he's breaking the menu into three sections: garden, ocean and grassland. There will be dumplings, noodles, Korean short ribs and duck wings, for example.

They'll also keep the "fun" aspect that Fat Belly's has; with Sake, tequila and rum bombs. There will be drinks called the Fuki Sour, Red Lotus and Sling Blade.

Squier said it's also his hope to do "secret menu items" that are an ode to Fat Belly's; an Asian play off some classics.