About 400 years after his death, Adm. Yi Sun-sin has gripped the entire nation. A movie about his triumph over the invading Japanese fleet is smashing all the box-office records. The film is leading to a sensational boom in the related publishing, tourism and even in online retail businesses.

“Roaring Currents,” a period action film portraying the legendary 16th-century admiral, drew 10 million viewers in 12 days. It is the 12th film ever to have sold more than 10 million tickets, and it did it in the shortest time. The previous record was held by “The Host,” which took 22 days to draw 10 million people.

Its record-breaking pace is striking. It set the record for biggest audience on an opening day with 680,000 tickets, for a weekday with 980,000 and for a single day with 1.25 million. Industry officials expect the film to top all the remaining box office records, including those for total ticket sales, which are held by “Avatar” with 13.3 million and “The Host” with 13.02 million, the latter being the record for a Korean movie.

Why are Koreans so fascinated by a film which is based on what they learned in elementary school? Some detractors mention a herd mentality, a lack of rival films, and the distributor’s superb marketing skills and dominant network of theaters.

But what seems certain is that respect for a man who devoted his life to defending the country from a foreign enemy is one of the driving forces behind the film’s explosive popularity. Viewers are also drawn by his leadership, which is exemplified by the defeat of a fleet of more than 300 enemy ships with only a dozen vessels under his command.

In fact, Yi, who once suffered political suppression and had to overcome many other odds, usually comes top in polls asking people to choose the person they respect the most. There have already been many books and classes on his leadership.

Many pundits and commentators say the sensational success of the film shows that contemporary Koreans long for a real hero and true leader, whom they have not seen for a long time. The film’s success also reflects Koreans’ frustration with politicians and other elite groups.

Many politicians, including President Park Geun-hye and the ruling and opposition party chiefs, have seen the film. One wonders what they would have thought when Yi, played by Choi Min-sik, said: “A soldier must be loyal to the people, not to the king, because without the people there is no nation and without a nation there is no king.”