9 timestamped notes explaining the Korean cultural context in this episode — customs, idioms, food, honorifics, and history, at the moment each appears on screen. These notes discuss events across the whole episode. To see them revealed scene-by-scene as you watch, use the episode page to find an airing.
Korean apartment doors almost always have a digital keypad instead of a physical key. Couples commonly set the code to a meaningful date — here the wife immediately rattles off their wedding date, July 20th (0720), as the password. The fact that the husband had to ask is a quiet signal of how far apart they've grown.
The caption identifies the caller as a '조리원 동기' — a friend made at a 산후조리원 (sanhujojiwon), a dedicated postpartum recovery centre where new mothers typically stay for one to two weeks after giving birth. These centres provide meals, infant care, and recovery support, and the women who share a stay often form close, lasting friendships.
흑채 (heukchae) is a powdery spray or fibre product that temporarily colours and thickens thinning spots on the scalp — essentially a black camouflage for hair loss. It became a well-known product in Korea and is widely recognised as something middle-aged men reach for before admitting they need treatment. Spotting it on a friend's head is a gentle but unmistakable tease.
Jin-ju is startled to see a 소독차 — a municipality pest-control truck that drives through residential neighbourhoods spraying insecticide, usually in summer evenings. These trucks were a very common childhood memory for Koreans who grew up in the 1980s–90s, and kids would often chase after the white fog. Seeing one now, as an adult who has time-travelled back to 1999, reads like a nostalgic landmark.
Jin-ju breaks down and says she wants to die and asks her mother to take her along. In Korean grief culture it is not uncommon to speak to the deceased as though they can hear, especially at a grave or memorial. Her words here are an emotional outpouring of despair rather than a concrete plan, but the show treats them with care rather than dismissing them.
The banner welcoming '99학번 신입생' means the class entering university in 1999. Korean universities traditionally hold intense orientation periods (OT) where seniors run activities, enforce wearing the 과복 (department uniform — here the navy-and-white 'pickled-radish' outfit the engineering students wear), and establish a strict sunbae-hoobae (senior-junior) hierarchy. Being caught without your 과복 was a genuinely big deal.
공과대 (engineering college) freshmen in the 1990s wore matching department uniforms called 과복, often in white and navy stripes. The colour and pattern earned them the nickname 단무지 (danmuji) — yellow pickled radish — from other departments. Wearing it was compulsory during orientation, and skipping it meant facing senior wrath, which is exactly what lands Ban-do in trouble here.
One of the men spots actress Bae Suzy on a phone screen and calls her '국민 첫사랑' — literally 'the nation's first love,' an affectionate title Korean media gave her after her breakout roles playing wholesome, girl-next-door characters. The title stuck and became a widely used nickname. Using it here is a quick shorthand for a certain kind of pure, unattainable crush.
미팅 (meeting) in Korean university culture refers to a structured group blind date — typically four or five men from one department meeting the same number of women from another, at a café or restaurant. It was the standard social mechanism for meeting potential romantic partners in the 1990s–2000s campus world, and organising or attending one was a rite of passage. The cliffhanger suggests this is the very 미팅 where Ban-do and Jin-ju first met.