In Dear Hongrang Episode 4, the story begins with the nobleman ordering Jae-yi’s execution to ensure she doesn’t jeopardize Hong-rang’s cover. At the same time, Yeon-ui calls a merchant guild meeting, declaring she’ll reward those loyal to her and Hong-rang while eliminating those siding with Yeol-guk. The merchants inform her that winning over the patrons is the key to shifting the guild’s support.

Yeol-guk learns about the meeting and sets a trap involving a forged painting. While carrying out the plan, he encounters a cloaked woman whose scent brings back memories of his former lover, Kkot-nim. A flashback reveals that Kkot-nim was pregnant, and though Yeol-guk wanted to flee with her, Yeon-hui locked her away and made him choose. He chose to stay. After her disappearance, Kkot-nim’s brother Mun Gyu-ha blamed Yeol-guk and drowned his sorrows—rumored to have drunk himself to death.

In the present, Jae-yi collapses from hunger, prompting Hong-rang to take her to a clinic. While unconscious, she dreams of Little Hong-rang holding her hand, only to awaken to the real Hong-rang mirroring that exact gesture. Returning home, Jae-yi is emotionally drained. Mu-jin apologizes and expresses his willingness to accept Hong-rang as their real brother. Hong-rang overhears and pieces together the truth—Mu-jin was the one who swapped the wine, and Jae-yi took the blame to protect him. This realization frustrates Hong-rang, especially since she kept it from him.

Soon after, Hong-rang is summoned to visit his great uncle, with Yeol-guk approving the journey. He asks that Jae-yi accompany him, a decision that displeases both Mu-jin and Yeon-ui for different reasons. Meanwhile, Yeon-ui attempts to win over a patron, Lord Hong, by gifting him a painting. However, Yeol-guk later presents the same artwork, causing confusion. It’s revealed that Yeon-ui’s version is a fake, while Yeol-guk’s contains the Jin appraiser watermark, proving its authenticity. Furious, Yeon-ui discovers that all the paintings in her storage are forgeries, meaning she’s unknowingly gifted fake artworks to every patron.

While traveling, Jae-yi and Hong-rang bicker when she insists on helping a baby bird. Despite teasing her, he helps her return it to its nest. Beneath the surface, he battles with the fact that he’s been ordered to kill her during this trip. Upon reaching their destination, his uncle tests him with fire—a nod to the tragic fire that scarred Hong-rang’s real family. Fake Hong-rang doesn’t react and claims he’s endured worse while being held captive. The uncle appears satisfied but warns him about the consequences of harming the innocent.

During a brief stop, Jae-yi goes for a swim, catching Hong-rang off guard. While distracted by his feelings, he notices assassins closing in. He draws them away and defeats them easily. A flashback reveals Mu-jin had ordered the assassins to protect Jae-yi, fearing Hong-rang might harm her. However, after Mu-jin left, his subordinate secretly paid the assassins extra to have Hong-rang eliminated.

Later, Jae-yi frantically searches for Hong-rang, terrified that he disappeared again. When she finds him, a sudden scare causes her to instinctively shield him, which amuses him, though she brushes it off. She then notices that he’s bleeding and is overwhelmed with tears of frustration that he’s constantly putting himself at risk.

Back in the capital, Yeon-ui seeks help from a shaman, who cryptically remarks that a fake cannot exist when an original is present. Inspired, Yeon-ui pressures the Jin appraiser to claim Yeol-guk’s painting is a forgery. A flashback shows her threatening the man into lying about the watermark. To cover her tracks completely, she burns down the Jin vault, destroying every real painting. She echoes the shaman’s words as Yeol-guk watches in disbelief, horrified that she would go so far for the sake of her reputation.

At an inn, Jae-yi feels embarrassed by her emotional reaction, while Hong-rang appears pained by her empathy. In-hoe quietly observes this change but Hong-rang dismisses it as pity. Once they return, Yeon-ui—still savoring her apparent win—is surprisingly kind to Jae-yi. But trouble looms. The nobleman scolds Hong-rang for not killing Jae-yi, but Hong-rang counters that she can still be useful because of her Sim blood. All he needs to do is win her trust. A woman nearby questions if he really believes that’s possible.

In a twist ending, the nobleman unexpectedly encounters Yeol-guk, who is stunned to realize it’s Mun Gyu-ha. He lashes out at Yeol-guk, blaming him for Kkot-nim’s demise. The final scene delivers a bombshell: the woman beside Hong-rang, who had doubted him earlier, is none other than Kkot-nim. And Hong-rang greets her with a quiet, “Mother.”