Sometimes the best investment opportunities when it comes to restaurants are the ones you've never heard of. Where the name of the game with a profitable concept is "locations, locations, locations" (plural), it's the one thing, and maybe the only thing, that Kona Grill (NASDAQ: KONA) is lacking, while more familiar names such as Chipotle Mexican Grill (CMG 6.64%) and Buffalo Wild Wings (BWLD) are not. Kona Grill may be small now, with only 26 restaurants, but that appears to be changing in a big way.

Who or what is Kona Grill?
Are you in the mood to hit a sushi bar, grab a fancy sandwich, or would you prefer a quality steak at an upscale restaurant? At Kona Grill, it's all of the above and more. Its double-sided menu consists of all sushi on the front and fancy eats and finger foods on the back.

Curious about the place, I popped in one on Feb. 13 (earnings day). I was warned that the sushi may take a little longer than usual because the place was much busier than they expected, and they were caught off

guard. Sure, it's one location during one mealtime slot, but that perked my ears up and got me salivating about a possible investment. But this isn't about me; it's about the results and where Kona Grill is headed, even though the food and ambiance were quite impressive.

Kona-licious results
On Feb. 13, Kona Grill reported fiscal fourth-quarter results. Revenue jumped 6.5% to $24.5 million. Same-store sales bumped up by 3.5%. The net loss per share was $0.06, but it included $0.20 of temporary charges. Excluding this charge, earnings per share leaped 40% to $0.14.

Chief executive Berke Bakay pointed out that it was the third consecutive quarter of same-store sales gains, and it came despite "a shortened holiday shopping season and inclement weather." Kona Grill has widened the gap against the rest of the industry, with a 2.7% gain compared to a 3.7% average decline in traffic for the rest of the industry, a difference of 6.4%.

Prior to the quarter, Kona Grill had not opened a new restaurant in more than three years. During the quarter, the company owned two new restaurants. Bakay has declared the company to be back in growth mode. The average sales of the two new restaurants were $100,000 per week compared to $80,000 on average for the rest of the chain.

Kona Grill is looking to add four more restaurants in 2014 and accelerate from there into 2015 and beyond. Its goal is to double sales within five years, and it looks like based on progress it may achieve that well ahead of schedule. Bakay added, "Excitement around our brand is intensifying as we accelerate new unit growth."

As Bakay noted during the conference call, the company's peers are scaling back their growth plans while Kona Grill is accelerating its plans due to confidence in its brand stemming from the results it is seeing.

Grow like Chipotle and Buffalo Wild Wings
After watching shares of Chipotle Mexican Grill and Buffalo Wild Wings rise into the stratosphere, it's always a good idea to be on the lookout for small chains that could become the next big thing. At one point in time you hadn't heard of either, but you probably wish you had.

Chipotle Mexican Grill had its IPO at just $22 and currently trades at more than $550 per share. For 2013, the chain reported more than $10 per share in earnings for a P/E of 2 against its original IPO price. Had you both heard of and knew where Chipotle Mexican Grill was headed back then, you'd be up an incredible 2,500%.

Meanwhile, Buffalo Wild Wings is also on the list of, "Why didn't I jump on board sooner?" With its IPO of a split-adjusted $8.50, Buffalo Wild Wings is currently up around 1,500% over the last decade. Not too shabby. Could Kona Grill be the next restaurant stock darling over the next 10 years? 

Foolish final thoughts
With Kona Grill trading at 28 times next year's expected earnings, it may seem a bit pricey at first glance. Patient Fools should still consider giving Kona Grill a chance, as the current low store count means there is enormous potential to accelerate the top and bottom lines on a percentage basis.

Keep in mind that Kona Grill won't necessarily be the next Chipotle Mexican Grill or Buffalo Wild Wings; but with a market cap of less than $200 million, it doesn't have to be to still reward Foolish investors.