Episode 8 of "Friendly Rivalry" kicks off with a bombshell revelation from Je-yi, who discloses that she procured Seul-gi's confidential documents from her father's office. Intriguingly, she confesses a surprising sentiment of camaraderie, expressing her contentment at sharing the pinnacle with Seul-gi, signaling a subtle yet profound shift in their relationship.
The narrative then takes a eerie detour as the students undergo a medical procedure under anesthesia's deep embrace. During this surreal state, Seul-gi is ensnared in a vivid dream that transports her back to a childhood beach excursion, where she wanders aimlessly in search of her father. Amidst her confusion, Je-yi emerges like a guardian angel, aiding her younger counterpart.
Elsewhere, while Seul-gi slumbers unaware, Je-yi's suspicions towards Ye-ri's clandestine activities peak but remain unsatisfied as she fails to catch Ye-ri red-handed. As the school festival unfolds in a joyous ambiance, Seul-gi and Je-yi find solace in each other's company, momentarily shielding themselves from the turmoil enveloping their lives.
However, beneath the festive exterior, Ye-ri is orchestrating a plot of her own. Earlier, she had stealthily procured Seul-gi's father's phone, only to find it dead upon attempting to probe its secrets. To procure a charger, she strikes a deal with a classmate who happens to be Je-yi's regular customer for study-enhancing drugs, offering a coveted invite to a blind date event in exchange.
Concurrently, Choi Gyeong embarks on a quest to update Seul-gi about her father's case but crosses paths with Ye-ri instead. Enticed by Ye-ri, Choi finds herself on a blind date with Byeong-jin, who subtly slips her a drug, tasking her with delivering it to Seul-gi. Once the date concludes, Ye-ri cunningly leaves Seul-gi's father's phone charging beneath a table and proceeds to meet Je-yi's father—a meeting that unveils a shocking twist: he is the one who orchestrated the phone's theft. Unbeknownst to Ye-ri, Je-yi had entrusted a classmate to tail her, and upon learning of their clandestine encounter, Je-yi abruptly deserts Seul-gi.
Seul-gi eventually reconnects with Choi Gyeong, only to discover her phone missing. Fortunately, Je-yi uncovers it hidden within the blind dating tent. As she receives a mysterious, silent call, curiosity propels her to unlock the phone using a password inspired by Seul-gi's missing person poster. The revelation that greets her is nothing short of devastating—a video of her sister, Je-na, in a compromising position with Seul-gi's father, accompanied by threatening text messages blackmailing him with the footage.
As the truth begins to unravel, chaos ensues in other corners. The student to whom Ye-ri had pledged a blind date, spurned by the breach of promise, unleashes her fury. In a blinding rage, she draws a knife and begins to menace everyone within reach. Matters take a dramatic turn for the worse when she lunges at Seul-gi, slicing her shoulder, all while Je-yi finally confronts her long-absent sister in the school counselor's office, the scene charged with emotional intensity.
