The fourth episode of "You and Everything Else" commences with Sang-yeon and Eun-jung engaging in a nostalgic conversation, each reflecting on their past selves. Eun-jung confesses that she never truly embraced the academic life, absconding from high school after just two months. Sang-yeon, on the other hand, crafts a lie, asserting that her brother has recently returned from the military and is thriving at college as a business major. Her matter-of-fact tone causes Eun-jung discomfort, contrasting sharply with Sang-yeon's surprise when she learns that Eun-jung and Sang-hak are now romantically involved.
The episode delves into Sang-yeon's family's financial woes, revealing that they have succumbed to bankruptcy. Ms. Yoon, once the warm and nurturing teacher, has transformed into a distant figure in Sang-yeon's memory. Her parents' divorce has further complicated matters, leading to a rift with her father that makes for an awkward conversation with Eun-jung.
In stark contrast, Eun-jung finds herself in a different predicament, having moved several times and now assisting her mother in running a tteok shop alongside her uncle. Sang-yeon works tirelessly, doing whatever it takes to make ends meet, a stark contrast to the girl who once lived the high life. Eun-jung feels a sense of regret watching Sang-yeon's descent from grace.
As they discuss money and its role as a status symbol, an underlying tension arises between them, reflecting their shifting fortunes. However, as Sang-yeon begins to settle into college life and even challenges Sang-hak during a seminar, an awkward silence looms between them after Sang-hak is humiliated in front of the class. Despite this, the trio manages to iron out their differences, leading to a surge in their friendship and a surge in their hangouts.
As the year progresses, Sang-hak is affectionately addressed as "oppa" by all, except for Sang-yeon and Eun-jung, who both have their own reasons. It seems that Sang-yeon harbors a secret crush on Eun-jung's boyfriend, a fact that she subtly hints at by continually turning down other classmates' advances and spending more time with Eun-jung without her. Eun-jung, worried that her boyfriend might leave her, is further troubled by Sang-yeon's flimsy tale of meeting someone online, stalking them, and finding out they had a boyfriend. It is clear that Sang-yeon is also interested in Sang-hak.
As Eun-jung's photography skills blossom, she starts to feel more ordinary and believes that none of her photos have the "wow" factor. This leads to her lashing out at her boyfriend over her perceived lack of talent. Eun-jung is determined to move out and live on her own terms, but she needs money, specifically to live with her boyfriend. When Sang-yeon learns that Sang-hak has enlisted in the military, it changes her mood.
Sang-yeon, who rarely thinks of her brother as dead, prefers to pretend he is thriving. She eventually decides to lead Eun-jung and Sang-hak to visit her mother. However, Ms. Yoon is not in good shape. She looks haggard, has very few possessions, and her fridge is almost empty. Sang-yeon casually drops Sang-hak's name and calls him "oppa," acting cold and aggressive towards her mother. The hostility between them makes everything awkward.
As they leave, Ms. Yoon brings Eun-jung back inside and shows her the letter addressed to Sang-hak, which he never received. Ms. Yoon reads the letter without asking but admits it is beautiful. The clover is still inside too, and Ms. Yoon is grateful that Eun-jung gave something so precious to her son. Eun-jung struggles to hold back the tears.
Outside, Sang-yeon vents to Sang-hak about her mother and how she was always the odd one out in the family. He empathizes with her about her tough life, and when Eun-jung heads outside, she notices Sang-hak and Sang-yeon staring at each other with a mix of emotions.
