In the second episode of Dear X, Ah-jin visits the resting place of her mother, Lim Sun-ye, her heart heavy with unspoken secrets. She confides that she falsely claimed her childhood abuse had left her wrists damaged to evade a submission deadline in art class. This is why the art teacher encouraged her to seek counseling, a journey that echoes the flashback to June 2007.
As Sun-ye takes young Ah-jin to a convenience store, instructing her to steal two bottles of soju, tragedy strikes, and she passes away that night. Her father, Baek Sun-gyu, then embarks on a new relationship with Hwang Ji-sun, whose husband also died under mysterious circumstances. Ji-sun's son, Joon-seo, becomes Ah-jin's unexpected connection. However, Joon-seo's grandfather holds Ji-sun at bay from touching his inheritance.
That fateful night, Ah-jin overhears Sun-gyu conspiring with Ji-sun to sell videos of her for profit and abandon her in an orphanage. In 2016, immediately after the events of Episode 1, Sung-hee spots Sun-gyu snooping around Ah-jin's school. She sees this as an opportunity to humiliate Ah-jin and lures Sun-gyu inside the school. Once again, Joon-seo intervenes, dragging Sun-gyu away with a promise of cash if he stays away from Ah-jin until she graduates.
As Ah-jin watches her father and Joon-seo from afar, an entertainment company CEO, Seo Mi-ri, catches her eye on the street. Joon-seo gives Sun-gyu half of what he promised and urges him to stay away. As he departs, Seo Mi-ri approaches Ah-jin and expresses her interest in making her a star. Ah-jin politely declines.
Meanwhile, Jae-o receives a panicked text from his little brother and rushes home to find his father in a delirious state, attacking his brother with a knife. Jae-o manages to stop him but in the ensuing struggle, he ends up stabbing his father. He sends his brother to stay with his aunt and calls Ah-jin to share his predicament. He decides to turn himself in, and Ah-jin advises him to feign tears and remorse to secure a lighter sentence.
In the days that followed, Sung-hee embarked on a new chapter by transferring to a different school. Meanwhile, in 2017, Jae-o found himself behind bars, facing a sentence of 3-5 years due to the intricate nature of his circumstances. Ah-jin's words resonated, "Tears do work." She was accepted into the prestigious law school at Hanguk University, where Joon-seo had also secured his spot. With the tuition fees looming large, Joon-seo turned to his grandfather for financial assistance, requesting a loan to help Ah-jin. The grandfather agreed, with a catch—Joon-seo would accompany him on a three-day trip to Japan for medical treatment.
Sun-gyu's gambling spree had left him penniless, and he set his sights on finding Ah-jin once again. He paid a visit to Ji-sun, inquiring about the whereabouts of the children. Joon-seo delivered his grandfather's money to Ah-jin, who hesitated briefly before accepting it. However, when she returned home, she was met with a shocking turn of events as her father violently beat her and snatched the cash.
A flashback revealed Ah-jin's tender care for young Joon-seo when he fell ill. She showed him a picture of himself with his parents and his father's driver. The next day, as the housekeeper escorted Joon-seo to the hospital, Ah-jin confided in Ji-sun that she knew Joon-seo's true father was Mr Kang, the driver, not her ex-husband. She used this knowledge as leverage to ensure Ji-sun wouldn't send her to an orphanage, even procuring new clothes in the process.
When Joon-seo returned, Ah-jin shared with him the harsh truth about his mother's love. Overhearing this exchange, Ji-sun complained to Sun-gyu, who instructed her to take Ah-jin outside. Ji-sun grabbed Ah-jin and led her to the bathroom, attempting to drown her in the tub. Joon-seo's timely intervention stopped Ji-sun in her tracks. Ah-jin instructed Joon-seo to call 911 and made a run for it, jumping out of a bedroom window.
As predicted, Ah-jin survived and the adults' attempts to send her to an orphanage were foiled. In the hospital, Joon-seo revealed that he had read Ah-jin's diary, which described a bad person named X. He realized X referred to Ji-sun and was now convinced that she was indeed a bad person. He told Ah-jin that he would never let go of her hand.
In the year 2017, Ah-jin finds herself once again in the hospital, her hand firmly held by Joon-seo. He informs her of the devastating news that she has been unconscious for a span of three days. This unfortunate turn of events has caused her to miss the deadline for her university admission, an opportunity she had been eagerly anticipating. The very next day, their high school graduation ceremony looms ahead. Ah-jin's mood is heavy, a tangible weight in the air as she walks away from the ceremony, Joon-seo close behind.
As they stroll down the street, Ah-jin catches a glimpse of a man giving chase to a thief, and it seems to captivate her attention in a way that would alter the course of his life. The narrator's voiceover intones that if she had not stumbled upon him at that moment, their lives would have taken a completely different path.
The episode concludes with Jae-o sketching a picture of Ah-jin in prison, a haunting image that symbolizes the unexpected twists and turns that life can take.
