As KBS drama "Moonlight Drawn by Clouds" hits 20 percent viewership ratings in its seventh episode, there is a highest possibility the drama will take over the position of "Descendant of the Suns" as the highest rating drama.

"Descendant of the Sun" topped the record with the highest rating at 40.5 percent in Seoul Metropolitan area and 35.3 percent nationwide, according to TNMS rating. The number was reached when its final episode was aired on April 14, 2016.

According to Yonhap News Agency, "Moonlight Drawn by Clouds" hits 20 percent rating in Seoul metropolitan area on Tuesday Sept.13, based on the Nielsen Korea rating. While according to TNMS, the previous episode has already hit the 22 percent rating nationwide.

In Korea, there are two rating system to calculate viewership standing and they were provided by two different companies, TNMS and Nielsen Korea. Both are using the same methodology and the same number of sample, therefore difference in results between the two of them are very low.

"Moonlight Drawn by Clouds" which can loosely translated "as Love in the Moonlight" has its ratings continue to climb up since first aired on Aug. 22.  The fictional story of "Moonlight Drawn by Clouds" is based on the real-life  Crown Prince Hyom Yeong who was born Lee Yeong and ruled Joseon as King Munjo from 1827-1830.

The story revolves around unlikely love story between him and an 18-year-old girl, Hong Ra-On, who masquerades as a eunuch. Actor Park Bo-Gum is cast as crown prince Lee Yeong, while Kim Yoo-Jung plays Hong Ra-On.

In order to make the drama more captivating, the producer adjust Lee Yeong's character to be more playful than his depiction in the webtoon. The adjustment worked well since the beginning of the drama, as its premiere episode scored 8.7 percent viewership ratings nationwide and 10 percent in Seoul on TNMS rating.

As rating for "Moonlight Drawn by Clouds" continue to climb, its competitor SBS period drama "Scarlet Heart" decline slightly from 6 percent to 5.7 percent, Soompi reported.

"Moonlight Drawn by Clouds" will run for 18 episodes. Next week the ninth and 10th episode will air on Sept. 19 and 20, respectively, on KBS.