In the seventh episode of "You and Everything Else," Sang-yeon and Eun-jung's confrontation over Sang-hak takes a dramatic turn. Sang-yeon spins a web of lies, claiming her beloved is a guitarist in a band, when in reality, the truth is a twisted web of gaslighting. Eun-jung struggles to hold back tears, doubt creeping in at every word. Sang-yeon, nonchalant as ever, dribbles out the truth in bits and pieces, eventually admitting it's about Sang-hak but keeps Eun-jung at arm's length.
Eun-jung, desperate to believe Sang-yeon, is consumed by anxiety, paranoia, and worry. She becomes obsessed with discovering the truth, checking her postbox constantly for more letters and rummaging through her things.
To throw Eun-jung off the scent or to help her friend (it's hard to discern Sang-yeon's true motives), she deliberately decides to date another man. Over dinner, he asks about their past, and Eun-jung admits her envy of Sang-yeon's talents, including dancing and studying. But Sang-yeon reveals that her own insecurities stem from Eun-jung, though she doesn't say it out loud. It's clear what she means.
Eun-jung shows up at the base to see Sang-hak, noticing the watch he's wearing. It's a constant reminder of Sang-yeon's influence over her boyfriend, fueling her anxiety further. However, she believes Sang-yeon is doing her best, especially when she shows up to help her mother at the restaurant.
This moment seems to be a crucial turning point for the two of them as they start to act like friends for a little while, at least on the surface.
Shortly after, Sang-hak receives a letter from Sang-yeon, requesting to meet Dylan (Moon Ji-yeong) as a final favor. He obliges, but Dylan beats him to the base. She presents a letter and confides in him that she's in a tight spot. Sang-hak then heads to see Sang-yeon, updating her on the developments and taking a leave of absence from the base. He lies to Eun-jung about his reasons, claiming it's for her upcoming big exhibit.
Earlier, Sang-hak had passed on Dylan's number to Sang-yeon, urging her to reach out to the woman. Sang-yeon takes the bus to Ji-yeong's house in the mountains, preparing to depart for Canada. Sang-hak is preoccupied at the gallery with Eun-jung, worried about Sang-yeon's journey alone.
When Sang-yeon arrives at Ji-yeong's, she discovers that Sang-hak had often spoken of her. Though they were never lovers, they were close friends, a bond that even Ji-yeong's mother approved of. Furthermore, it's revealed that the 'M' Sang-hak had been writing to was not Ji-yeong.
In truth, Sang-hak had never fully embraced his own identity, and the name Moonee was a reflection of his persona. Dylan understood this and was there for him. Upon hearing this revelation, Sang-yeon vanishes, leaving Sang-hak in a precarious position. If he reveals Sang-yeon's presence, he'll be exposed for his lie to Eun-jung. Yet, if he simply leaves, it will appear as if he's betraying his girlfriend, making his situation even more complicated.
Sang-hak drives to Sang-yeong, weaving a web of lies to Eun-jung about his true intentions. The atmosphere is charged with an ominous vibe, and when Sang-hak finally catches up with Sang-yeon in the woods, she is a sobbing mess. The truth is a bitter pill to swallow, especially when Cheon Sang-hak keeps so much of his life hidden under lock and key. However, Kim Sang-hak's secrets are teetering on the brink of destroying his bond with Eun-jung. When he arrives to pick up Sang-yeon, Eun-jung is fuming, having discovered he wasn't home. To make matters worse, Sang-hak turns off his phone.
After time to ponder and calm down, Sang-yeon confesses that there were telltale signs in the past. That picture of Sang-yeon as a child dressed as a girl? It turns out that was actually Sang-hak in preschool, always fond of playing with dolls but forced into sports or among other boys by their father. Unfortunately, he also resorted to violence when Sang-hak didn't comply.
The truth is ruthless and devastating, mirroring Eun-jung's own when she storms into Sang-yeon's room and discovers the letters hidden away. She's convinced there's a romantic connection, unaware that it's one big misunderstanding shrouded in secrecy.
Sang-hak appears at the gallery, only to find himself embroiled in an argument with Eun-jung. She's livid, especially when she realizes that Sang-yeon has always had feelings for Sang-hak and lied to Eun-jung about it all. She speaks of her "unforgettable night" and how she confessed her liking for him, which, coupled with Sang-hak's phone being off, doesn't exactly paint him in a favorable light. He eventually admits he drove out to fetch Sang-yeon, but Eun-jung presses him on his feelings and where his heart truly lies.
Sang-hak confesses that his heart has been swayed by Sang-yeon's presence.