What started off as a joke and an ultimatum has since become a roaring online business for Gerald Shen and Diana Chan. The married couple run Vanda Fine Clothing, which creates handmade neckties and pocket squares.

Mr Shen and Ms Chan, both 29, first met back in 2003, when they were students in the same junior college. But they only started dating after they left school, in 2004, and got married in 2013.

Back in the day, the couple shared a hobby, of making pocket squares for Mr Shen's personal use. "I would ask Diana, can you make me a pocket square?," says Mr Shen. Ms Chan, who has an interest in sewing, and would often take apart clothes and put them back together again, took on the challenge.

With the extra pocket squares that she made, Mr Shen began selling them through an online forum, to much success. "The money made paid for our holidays and expenses," says Ms Chan.

Seeing how there was a huge market for handmade pocket squares - most of their customers were and are still from the US - Mr Shen would often joke with Ms Chan about starting a business creating these pieces. But for a long time, it remained an idea.

He would be the one taking orders, while she does all the sewing. Their idea of a date was not going to the movies, but the two would often be holed up at their parents' homes filling up orders.

"One day, I gave Gerald an ultimatum. Either he learns to sew as well or we give up doing it altogether," says Ms Chan.

At the back of his mind, Mr Shen was thinking about starting a business, and since he often joked about running a business with Ms Chan, they decided to turn it into reality.

"We both liked the idea of turning this hobby into a business. We had nothing to lose, and if we failed, we would look for jobs," says Mr Shen. Vanda Fine Clothing started in 2011.

"My first reaction, when I had to learn sewing, was one of disbelief," says Mr Shen, who has since gotten the hang of it, and at times finds it calming. Ms Chan chimes in: "Gerald's sewing skills are very good now. Even when I look at a completed piece, I cannot tell who has sewn it."

The two run the business full-time with two employees. The tasks are split between them all, depending on competency. For example, Mr Shen is in charge of cutting the fabrics, such as vintage kimono fabrics from Japan, as well as other fabrics from Europe, into desired pieces.

Ms Chan, who is the more organised partner, is in charge of processing the orders. He says that she is better at coming up with product designs, while she says that he is better at thinking up business ideas.

They have their roles down pat, but Ms Chan says that during the early years of their business, they waged cold wars. Ms Chan cites the example of how when they stepped into the office in the mornings, Mr Shen would chill out a little, and enjoy his coffee before starting work.

Ms Chan, on the other hand, would dive head on into work immediately. "I would often ask Gerald why he is relaxing instead of working," she says. "It took me some time to figure out that if I gave Gerald time in the morning to do his thing, it would be a peaceful work day."

He on the other hand, found that his wife was not that great at prioritising tasks. "Diana is the sort that once she starts on something, she has to finish it, even though there are more urgent tasks at hand," he says. He would point out what should be done first, and in turn, she would take his advice and work on more urgent matters.

The cold wars would usually last half a day or the whole day. "We leave work together at the end of the day, so we would end up talking to each other by then," says Ms Chan.

The couple have spent time with each other nearly every day since they began dating. "Friends often ask how we can stand seeing each other, since we work together, and outside of work, but it's very natural for us," says Ms Chan.

Mr Shen says he loves his wife for being "extremely thoughtful", especially when he is sometimes forgetful and leaves things in a mess. "She'll be the one putting things back where they belong."

She on the other hand credits her husband for "taking my dream further". Ms Chan always had plans to create her own dresses, but "I'm not so ambitious".

"But with Gerald's support, my plan can be a reality." Indeed, the duo have plans to start a women's clothing line soon.

With their work cut out for them, the business can run smoothly even when one partner is away. "When Gerald is away on reservist, the processing of orders will be a little slower, but still manageable," says Ms Chan.

Mr Shen jokes: "If Diana goes away, I might be in trouble."