For cousins John and Jim Conway, ice cream is personal.

They grew up in the Mister Softee ice cream truck business, and were surrounded by people who counted on its success to support their families. Fifteen years ago, they took over the business from their fathers. The current lawsuit involving an imposter Mister Softee enterprise - Master Softee - is a financial drain and a stress for the cousins, but the Conway’s are fighting for the hundreds of people who are in the extended family, too.

“For our franchisees, who for the most part are Mom and Pop, small family businesses … it’s our obligation to protect them… This is a multi-level issue that affects a lot of people,” said Jim Conway, vice-president of Mister Softee, in an interview at company headquarters in Runnemede, N.J., a town of just over 8,000 people near the Delaware River and Philadelphia.

While the business is still going strong, it has been facing issues of copyright infringement from day 1, according to Jim Conway. It's a hassle that gets in the way of the family business.

The company has called Runnemede home since 1958, two years after the fathers of Jim and John first started slinging ice cream in Philadelphia. According to John Conway, James and William Conway’s first day on the job was St. Patrick’s Day.

“The story goes that on St. Paddy’s Day, they rode around and gave out free green ice cream. I was only three years old, so I can’t verify that,” he said, with a chuckle.

The headquarters of Mister Softee is made up of a few buildings: the offices in the front and the warehouses where the Softee trucks are built and painted in the back. The offices are a reminder of simpler times, much like the Mister Softee ice cream truck. The walls are wood-paneled, likely the same as in the late '50s. Posters and photographs from trade conventions in the '50s and '60s line the walls, a nod to simpler times.

Mister Softee had 1,000 trucks in the '60s, and there are about 600 operating today. But little else has changed.

"People have said, 'You should change the jingle, change the appearance,'" John Conway explained. "We say, 'Why change it if it works?'"

They did modernize the menu a bit when the cousins took over from their fathers: pictures of desserts replaced drawings of them. The trucks are now in 18 states, as far as Arizona and Missouri, and there are even trucks in China. A few brick and mortar stores are open on the Jersey Shore.

But the looming threat hangs over the company continuously. It's said that competition is healthy for business, but according to the Conway cousins, Mister Softee faces unfair competition nearly every year, and this year they had to take the Softee imposters to court.

The Master Softee trucks that have been opering in New York City look almost identical to Mister Softee trucks, from the cartoon ice cream cone to the design of the name painted on it. On June 5, federal court judge Laura Taylor Swain banned Master Softee owner Dimitrios Tsirkos, a former Mister Softee franchisee, from using the name Master Softee or any other similar names or truck designs. While some trucks have been scrubbed of the word "Master," amNewYork spotted one near Peter Cooper Village on 1st Avenue and 14th Street just four days ago.

It was a very hot day, and people were lining up for soft serve and milk shakes. All Mister Softee trucks use the same proprietary blend for shakes and ice cream, provided by Leiby's Dairy in Pennsylvania. So while the Master Softee truck's ice cream is different, the customers we spoke with didn't know it.

"I don't notice any difference," said Rich Williams, who works nearby at Beth Israel Medical Center and stops for a treat regularly. "I don't like it, but this is capitalism."

A call to Tsirkos' attorney Nicholas Damadeo was not returned Sunday, but Damadeo recently told the Daily News that an appeal to the court was being considered. Jim Conway said he wasn't sure why Tsirkos and three other franchisees had left Mister Softee for Master Softee.

Jim Conway says they have spent upwards of $30,000 in legal fees fighting Master Softee.

"Some people believe that imitation is a form of flattery, in our case it's a costly nuisance," he said.

But despite the nuisance, the history of the family business and the joys of ice cream keep the Conway's happy.

"I have two sons in the business," explained John Conway. "My oldest son runs the shop and my youngest son has his own trucks here in Runnemede. So I get to see them every day and work with them. And that's a real pleasure."