The hero of W, Kang Chul (Lee Jong Suk), lives in a world rather like ours. He won an Olympic gold medal for shooting, lost his family overnight in an unsolved murder mystery and has transformed himself, before his 30th birthday, into an e-commerce and media mogul.

It is all quite plausible, and yet, something about his life doesn't check out. Why would a truck literally materialise out of nowhere to nearly run him over? Why do bad things happen to him for no believable reason? Who or what could be behind them?

Why does a mystery woman, Oh Yeon Joo (Han Hyo Joo), who keeps appearing to save him before disappearing into thin air, know so much about him, even the fears and feelings he has never shared with anyone?

But she does sound sweet when she says she is a true fan, "one of those people who want your life to be a happy ending".

In a breathtaking episode of this K-drama, following a revelation that he is a character in a webtoon, Chul crosses into the world of his creator - the author of his unhappiness - looking for answers. He confronts the cartoonist (whom he discovers is Yeon Joo's dad), shoots him and jumps into the Han River, ending his life and his story.

It is only Episode 6, however, and the fun is just beginning. (Not to give the game away, but as followers of South Korean dramas must know, no hero will really, really die in an early episode, right?)

W is the work of Song Jae Jung, the writer who had a hand in a pair of tricky, graceful time-travel dramas, Queen & I (2012) and Nine: Nine Time Travels (2013), and this may be her craziest and cleverest show to date.

Queen & I and Nine play with the conventions of the time-travel genre, but W is far riskier.

It reveals but also revels in the unwritten rules of stories, be they webtoons, comic books or K-dramas. Through the tale of webtoon hero Chul and K-drama heroine Yeon Joo, it explores questions about genres, the destinies of characters and free will.

In Yeon Joo's analysis, although Chul was created as a character in an action cartoon, he should be free to become a romantic hero by her side.

But is he? Is it wishful thinking, even though wish fulfilment is a thrust of plenty of fiction?

Certainly, W is conscious of the fact that it exists in the world of coy Korean television.

With a nudge and a wink at emotionally satisfied, sexually starved K-drama fans, Chul asks Yeon Joo whether she would like to experience a "Cinderella story", an "everyday romance" or an "adult-only" romp.

She can choose, while viewers will just have to live with her choice.