Barely minutes into the South Korean drama Scarlet Heart, a prince disrobes in a well-appointed spa. He stops to flex his pectoral muscles - purely for the benefit of the home audience, presumably - then jumps into a hot pool to join a brother who is splashing about in a sheer shirt.

In a lounge near them, a third prince comes into view, abs first. Another glides in - ladies and gentlemen, please welcome ancient Korea's first male supermodel - and does a couple of twirls on a platform by the pool.

Enter two more princes, both in different states of undress, and there you have it: a little procession of calendar boys, one prince for each month.

The Korean Scarlet Heart is an adaptation of the 2011 Chinese time-travel show of the same title, although so much has been lost in translation, it feels more like a distant relative.

The Chinese Scarlet Heart is faithful to its source novel, whose innovation is to look at the well-known succession battle among the Kangxi emperor's sons from the chick-lit angle and wonder which of the Qing princes modern women would find more dateable.

Pacy and breathy, the Chinese drama is history lite, but also a portrait of how power is an aphrodisiac, as its time-travelling heroine already knows which prince will ascend the throne.

The Korean show is fluffier. It doesn't have a similar, specific episode in Korean history to revisit and there is little dramatic tension.

Instead, the tale has been recast as a generic-seeming love story: A young woman from the future (played by IU) catches the fancy of two princes of the Koryo kingdom (Lee Joon Gi, who plays the fourth prince, and Kang Ha Neul, who plays the eighth).

Although she recognises their father, Wang Kon, a legendary king whose story has been told on television, she doesn't really know his sons. Like viewers, she meets most of the princes for the first time in the spa, where she surfaces from the water after plunging centuries back in time.

She gets to know them, though not all that well. There's the eighth prince, who is scholarly, sweet and married. There's the fourth, who is murderous, sexy and still single.

Another prince (is it the 10th or the ninth?) is interested in her in a puppyish way, and at least one other brother (the 14th or 13th?) is indebted to her after she saves his life.

And that's the trouble. The Korean princes aren't as well-drawn as their Chinese counterparts and so, though they definitely seem to be wearing different amounts of eye make-up, they can be as difficult to tell apart as middling K-pop groups with more than five members.

There is no denying that the Korean drama is the more polished production, however, and has gorgeous moments as a pop-inflected mood poem about a bygone era. Men and women flutter their long eyelashes, rivulets of tears form and up-tempo songs flow, causing ripples of feeling within you.

It's all so pretty, but then, heart-stopping prettiness is a dime a dozen in Korean TV.