Despite the fact that Yoona and Lee Beom Soo have already shared their first kiss in "The Prime Minister and I," the ratings dropped even further to 5.4 percent. Which prompts the question: do these two stars have any real romantic chemistry together?

The two actors shared a kiss in a recent episode and even though it took place in a daydream, some netizens thought it was not all that romantic. Without real chemistry it is going to be hard to believe a drama in which a practical prime minister falls in love with a much-younger gossip magazine writer.

Chemistry between the leading co-stars is not enough to save a drama that is lacking in other areas but it can keep fans interested for long enough to get more involved in the storyline. And sometimes fans get so involved in the relationship between the characters that they hope the actors will date in real life. That's not likely to happen with Yoona and Lee Beom Soo.

When the decision to cast the actors was first announced many netizens were concerned about the age difference between them. Lee Beom Soo is 43 and Yoona is 23.

"They're practically father and daughter age," wrote one netizen.

Others were not concerned as long as their relationship was not an overtly romantic one.

"Everything is great," wrote another netizen. "But let's not have any kiss scenes. Let's keep it platonic."

But the plot calls for the actors to enter into a contract marriage and then fall in love. The two actors have already expressed how much they like each other and how comfortable they are working together. Yoona said that Lee Beom Soo was very kind and looked out for her on set.

At a recent press conference the actor spoke about Yoona's enviable energy and her work ethic.

"The most important thing is having confidence in your fellow actor," he said. "I believe that synergy can only develop when actors trust and respect each other. Yoona is good at this."

He thinks they have great chemistry but he's talking about the way they work together.

"We are very comfortable with each other on set and have even improvised some scenes. You can only feel that comfortable when you have a good partner."

But having a good on-set working partnership does not mean that the audience will buy your onscreen romance.

What do you think of these two actors as a romantic couple? Are they believable? Let us know.