Clue No.3: Love with thrills and chills

For example, one exchange between the captain (Yoo) and doctor (Kang), which goes, "Each time I want a light romantic drama with you, it turns into a blockbuster", and, well, this pretty much explains the appeal of the plot. Much of the action (and the plot) takes place in Uruk, Iraq, where the South Korean peacekeepers are based.

The complications start when the female protagonist (Kang) arrives as a volunteer doctor. As her love for the captain (Yoo) grows, the plot becomes a twisted mix of military missions, local conflicts, personal dispute, and war. And all of it makes this love story full of adventure, unexpected turns of events, and danger -- and really worth watching.

Clue No.4: Strong characters

Last and not least, this play finally dispenses with the clichéd script of so many South Korean TV soaps, where a sad male, supporting actor is obsessed with the female lead but never gets her love in return or a beautiful, jealous supporting actress tries her best to steal the lead hunk’s heart.

The roles in the drama are impressive and you will probably be surprised to find the four major players all adorable, but in different ways, giving most of the roles their own charm.

One example is the lead actress, Kang, who is in her early 30s, an excellent doctor, a lady pretty who works hard and is eager to success. But, in spite of the quality of her work, she has failed to get the title of professor for 3-years in a row because of her ordinary family background lack of power or connections; And she gets assigned to a remote country as a volunteer after refusing to sleep with the head of the hospital.

So, the story makes it quite clear from the first two episodes that this is an independent, talented, beautiful woman, and one with her own dreams but also her principles. She doesn't rely on anyone and can manage just fine without a man. This strong character is appealing on its own, so her new love with the captain is balanced and on an equal basis. This is what fans have called "well-matched" on social media.

No doubt, the reasons for the popularity of this TV series are complicated, but high on the list are: the large number of fans of the stars (Song Hye-kyo has been well-known in China for years), the promotion and publicity, and the simultaneous launch in South Korea and China. Whatever it is, Descendants of the Sun is worth watching for its content.