Wenfeng Gao

Geng Geng had been an ordinary girl before her entry to the best high school in the province by chance. She doesn't like her life there until she meets Yu Huai, her seatmate - their names make up the word "Geng geng yu huai", meaning "Unforgettable memories". They don't like each other at the beginning, but soon they start to understand each other.

One day, during the Qianlong period of the Qing Dynasty, the body of Mr. Wen, who was running a restaurant in Gyeongseong, is found dead. Upon arriving at the scene of the incident, Wang Seong-rim, a mailman from Suncheon-bu, finds a blood letter, but there are too many suspicious things to conclude as a suicide. Eventually, as a result of interrogation of Mr. Won's wife, he finds out that Mr. Won did not know the letters in his lifetime. At that time, Mr. Sa, who he had known well with Mr. Won, was murdered again with a similar technique, and Wang Seong-rim from Suncheon-bu, struggling to find a suspect, is on the verge of death...