The fifth episode of "My Royal Nemesis" commences with the news that the ominous star remains in the sky. Mun-do is staking out Kang Dan-sim's residence and finds amusement in Se-gye's frequent visits. Se-gye, bewildered by her own inexplicable fascination, can't stay away from her. Dal-su, on the other hand, is relieved that there's no romance brewing between his grandson and a nobody like Seo-ri.
Flashing back to the present, Se-gye confesses his affection for Kang. However, Kang, who also harbors feelings for him, lies and rejects him, leaving him speechless, as no one has ever rejected him before. The next day, Se-gye is in a foul mood and makes everyone's life miserable. Mun-do bribes the company's lawyer and discovers that Dal-su plans to transfer all his shareholdings to Se-gye.
Meanwhile, Kang hires a fortune teller to host a warding ritual to avert bad luck. Having been sold as a child, she decides to steer clear of Se-gye to avoid falling into Mun-do's trap. She also reconciles with Grandma Nam by claiming she's still Seo-ri, who picked up martial arts randomly.
A new scandal surfaces. The businessman who tried to cheat Se-gye in the first episode claims that he was the one who was robbed. Se-gye hits back by exposing all the dirt he has on the businessman.
Back to the romance, Se-gye realizes that Kang is playing hard to get. Son suggests pleading pathetically and love bombing the girl. The episode ends with Se-gye's determination to win Kang's heart and the tension between the two as they navigate their feelings for each other.
As the "mating war" heats up, a wealthy girl accidentally spills coffee on Se-gye's suit, but he barely gives her a second glance. It's time for Season 2 of Ji-hyo's historical drama, where Kang has a small role. She strives for historical accuracy, irritating the demanding director. Ji-hyo tries to humiliate Kang while also calming her down.
Kang's emotions fluctuate from sadness to happiness to annoyance when Se-gye surprises her with a coffee truck, which warms up the crew to her. He reveals that this is his way of courting her. She rejects him once again, and he angrily shoves roses at her before storming off. Ji-hyo, who has just been cheated on, assumes that Kang has a rich boyfriend and is upset.
The girl from the tailor shop reappears, hitting Se-gye's car. It turns out that she is a blind date, ordered by Dal-su to create a meet-cute. Se-gye rants to his psychiatrist, who thinks he's talking about company scandals. Jeong-hyeon suggests a new scandal and Se-gye applies it to his love life, agreeing to the blind date. Distracted, he ends up grabbing poisoned medication given by a bribed nurse.
Elsewhere, Kang reminisces about the time Prince Cheongheon helped her bury a stray dog and gave her flowers. There's a Jeju commercial shoot, and Kang decides to take the tenacious Gwang-nam as her manager. The commercial is organized by Se-gye's company, and he's going as well. He sits in business class while Kang grumbles in economy.
Soon, Se-gye passes out from the poisoned pills. Kang claims to be a doctor because she's good at acupuncture. But she freaks out, slapping Se-gye and begging him to wake up. He wakes up for a second, annoyed that she never leaves him alone. The flight attendants are about to use defibrillators when Kang holds his hand. Along with him, she gets shocked as well, and she realizes she needs to protect her heart. He wakes up and is stunned.
In the epilogue, we see that the flowers are for the dog's grave. Kang tries to keep her distance but Cheongheon gives her a rose and is quite romantic, asking to be her companion.
