Episode 8 of Bad Memory Eraser continues to unravel the complex relationships and mysteries surrounding Gun, Ju-yeon, Shin, and Sae-yan. The episode opens with Gun experiencing physical discomfort and disorientation, leading to a delayed arrival at a meeting. The coach expresses his anger over Shin's absence, and Sae-yan tries to distract him with Dalgona coffee while Gun searches for his brother.
Meanwhile, Shin confronts Guk-bong's accusations, denying any romantic involvement with Ju-yeon and explaining the misunderstanding surrounding the kiss. Despite Guk-bong's skepticism, Ju-yeon believes Shin's sincerity and agrees to collaborate with him to protect Gun's happiness.
Back at the meeting, the girls charm the coach, who agrees to take on Shi-on and Shin. As they leave, Sae-yan is excited about her first paycheck and tags along with Shi-on and Gun. Overhearing that Ju-yeon is not picking Sae-yan up, Gun offers to take her home, only to find her asleep.
Gun struggles to decide how to text Ju-yeon, who is also contemplating the same. When Sae-yan wakes up and scares Gun, he accidentally sends the wrong text to Ju-yeon. She becomes upset and seeks Gun's attention, but he abruptly leaves when Shin calls him.
Ju-yeon is annoyed by Gun's hot-and-cold behavior, which is exacerbated by Sae-yan's admiration for him. Gun scolds Shin for his playful attitude and promises to make amends with the coach. Shin claims he was on a date, and Gun playfully teases him. Shin tries to gauge if Gun still has feelings for Ju-yeon, but he deflects the question.
The next morning, both Ju-yeon and Gun are flustered as they prepare for their first day of work together. Dr. Han reminds Ju-yeon to avoid bias, and she quickly changes her outfit to something more casual. She is abrupt with Gun and instructs him to keep a feelings diary for his psychological evaluation. However, Gun scribbles in the diary and runs off.
Ju-yeon expresses her annoyance to Dr. Han, who accurately guesses that her feelings are interfering with her judgment. She becomes defensive but notices Dr. Han's flustered behavior due to Nurse Song's presence. Dr. Han changes the topic and reveals that he has been asking Gun to keep a feelings diary for the past ten years.
Gun, in a positive mood, heads to his investor meeting and discovers that he has been given preference over CEO Hong. The investor turns out to be Chairman Won's manager, and Gun secures funds for his agency. Hong is shocked and questions the manager about his agency, only to be told to return once he has Shin onboard.
Shin and his parents are at the hospital for a medical test and encounter the parents of other players. The parents are gossiping about Gun, and to boost his ego, Mrs. Lee claims that he is dating Ju-yeon. Ju-yeon tries to stop her, but Shin jumps in and adds that the doctor is with him, confusing everyone even further.
Alone, Ju-yeon tries to reprimand Shin, but he finds the situation amusing. She suddenly remembers Dr. Han's advice for Gun and asks Shin to find his old feelings diary. They realize that the diary likely contains all of Gun's hatred for his family and Ju-yeon.
Meanwhile, Gun is investigating his accident and cannot shake off the memories from the J Hotel on the night of the reunion. He asks the paramedics for help, and they direct him to the on-site detective. Gun learns that the accident occurred at the bridge and was caused by drowning.
However, Gun has to leave, and the detective informs Shin, who explains that Gun should remain unaware of his suicide attempt. The detective complies but finds it odd that there is no CCTV or dashcam footage, raising suspicions of foul play.
Gun heads to the bridge and experiences the pain from when Shin choked him that night. His vision is blurry, and he is unaware that Shin attacked him. Shin races home to collect all the diaries but discovers that one of them is in Gun's suitcase, which is at Ju-yeon's from when they switched bags. Sae-yan hides her paycheck in the bag and accidentally throws the diary outside.
That evening, Ju-yeon tries to maintain a distance from Gun to avoid misunderstandings. However, she falls while fixing a curtain, and Gun saves her. Their intimate moment is interrupted by Gun's parents, who have stopped by for dinner and invited Shin over. Gun goes out of his way to distract his parents, while Ju-yeon runs outside. Gun's parents try to inquire about Ju-yeon, and he insists that there is nothing between them.
Ju-yeon is sitting barefoot outside when Shin arrives with shoes and a blanket from his car. However, Gun's parents have already left, and Gun comes down with shoes for Ju-yeon. He ends up carrying Ju-yeon upstairs, and they bicker while a jealous Shin watches them.
Shin takes out his frustrations on Hong, who is trying to get him to renew a contract. Shin tears up the contract and leaves to sign with Gun, determined to be closer to Ju-yeon. Hong is furious and throws things around when he notices a photo that Sae-yan's father sent of Shin threatening Gun at the bridge.
Hong follows Shin to Gun's office and stops him just as he is about to ring the bell. Gun and Ju-yeon are about to open the door when they overhear their conversation. Hong threatens to tell Gun the truth, but Shin claims that his brother already knows about the drowning. Gun suddenly recalls hitting his head on the rails before falling into the water.
During this moment, Gun misses Hong showing Shin the photo. By the time Gun opens the door, Hong and Shin are gone. Ju-yeon promises to explain everything, but Gun is hurt by her lies. At the end of Episode 8, Hong deduces that Shin pushed Gun into the river.