Dhavajjai Sosothikul, his son Chaiyapat and a chemist friend are behind the success of Nanyang, one of the most popular student shoe brands in Thailand.
The company’s secret shoe formula is only known by three people, who have agreed never to take the same flight in case there is an accident, says Mr Chaiyapat.
The three have even agreed to never take the same flight so that, in the event of an accident, the 60-year-old company's secret formula will live on.
In 1953, Dhavajjai's father Wichai set up a small factory in Bang Wa in Bangkok to make student shoes and sandals, initially turning out only a few hundred pairs.
Today, the production capacity of all types of Nanyang shoes has climbed to 50,000 pairs per day or 20 million pairs per year, while its factory employs more than 1,000 workers.
The shoes are not only available in the Thai market but are also exported to Myanmar, Cambodia and China, earning sales worth billions of baht each year.
The business is now part of the Seacon Group, which has diversified largely to the retail and housing sectors under the Seacon Square Shopping Complex and Seacon Home brands.
Making shoes dates back to when the Sosothikuls' ancestors moved from China.
The business, which celebrates its 60th anniversary this year, is managed by mixed generations of the family, and Mr Chaiyapat is among four members of the third generation that work for the family business.
Mr Chaiyapat, 34, joined Nanyang Industry Co Ltd five years ago and was recently appointed deputy managing director.
Although he is a nephew of the founder, he has had to work in nearly all the firm's departments to gain experience.
Nanyang initially imported shoes from Singapore before the company decided to make its own in 1953 when the market's only branded student shoes were made by Bata of Canada.
It took about 20 years for the brand to become popular among Thai customers.
Quality is the key behind the success of Nanyang, which is the only company in the Asia-Pacific region that makes shoes from 100% natural rubber, Mr Chaiyapat said.
Every day, the company buys about 300 tonnes natural rubber locally to make shoes.
"With the use of 100% natural rubber, Nanyang's shoes are safe for wearers in all situations," said Mr Chaiyapat.
Apart from student customers, takraw players also use Nanyang shoes for practice and competition. Malaysia's takraw team are also customers.
Nanyang plans to extend production lines to cover various customer groups. It recently launched its Nanyang Have Fun line for children aged 5-9.
For the coming back-to-school campaign, it plans to spend 60 million baht on marketing promotions to grasp a bigger share of a market worth about 5 billion baht.
Nanyang is the market leader in canvas student shoes, selling more than 15 million pairs last year.
Sales of Nanyang shoes last year were up 18% from 2011.
Thanks to the continuous popularity of its footwear, the company plans to spend about 100 million baht to expand the production capacity of its Bang Kae factory by 20% from the current 20 million pairs per year.