"Our first night was July 4 and it was terrible. If there were normal customers, it would have been really bad," Mr Baldi said.
To test their product, the couple had invited only close friends and family.
"We had to change everything from the layout to the menu. We thought it was perfect, but it wasn't," Ms Nakamori said.
They said their small restaurant did not have a microwave or a freezer.
"It's real, authentic, fresh Italian food. We make our own bread and pasta and our fish is delivered fresh every day," Mr Baldi said. The restaurant was now so popular it was having to turn away 40-50 customers on busy nights.
The best way to taste its food was by booking.
The two said they were "a bit sad" for their friends, John and Sarah from Sabroso, who were number one on Trip Advisor until they knocked them back to second.