88 Line (88라인) Is a Birth Year, Not a Friend Group

Jung Hae-in was born in April 1988. Yim Si-wan was born that December. They’re eight months apart, and by the way Korea sorts people, they’re exact equals.

In August 2026, BIGBANG marked its 20th anniversary with a three-day run at Goyang Sports Complex. Hwang Kwang-hee posted photos from the concert with G-Dragon and Yim, plus a video taken while watching the show that had Jung in it.

TV Report filed all four under one label in its headline, 88즈, “the eighty-eights,” and described them in the article as four people born in the same year, 1988. Star News, writing up Hwang’s selfies, used the other form, 88라인, the 88 line.

I get why that label reads as “friends” from outside, but it’s a different claim. Two people can share a line without ever having met. What they share is a year.

One word does the sorting

A line is an everyday Korean word applied to famous people. The word is donggap (동갑, “same age”), and its characters say more than the English does. The Standard Korean Language Dictionary explains it as having the same place in the sixty-year cycle, the old system that gives each year a name.

So it’s the year, not the birthday. An April baby and a December baby from 1988 are donggap. A December 1987 baby and a January 1988 baby, a few weeks apart, aren’t.

The reason anyone keeps track is speech. With someone born even a year before you, polite speech is the safe default, and dropping it is theirs to offer. With a donggap, moving to banmal (반말, “half-speech”) is something either of you can suggest.

The dictionary’s first sense of banmal is speech that neither raises nor lowers the listener. Its second sense is talking to someone as though they’re beneath you, and the example sentence reads, “Who do you think you’re talking banmal to?” I think that one sentence explains lines better than any definition of friendship.

What the 2023 age law changed, and what it couldn’t

On June 28, 2023, amendments to Korea’s Framework Act on Public Administration and Civil Act took effect, widely called the age unification law. Ages in administrative and civil matters are now counted in full years from your birthday unless a specific law says otherwise. The government’s explainer said that covers laws and contracts, and also medication instructions and company rules.

The same explainer listed the exceptions that still run on the calendar year. For military service, your age is the current year minus your birth year. Under the Youth Protection Act, the birth year decides when you can buy alcohol and tobacco, whatever your birthday.

Lines never counted birthdays in the first place. I don’t think a law about counting from your birthday could have moved a single one.

Where the year rule used to bend

For decades, children born in January and February started elementary school a year early, alongside the previous year’s March-to-December babies. They were called ppareun nyeonsaeng (빠른 년생, “fast birth year”). Parents weren’t all keen on it: in the 2006 school year, 41.6% of January babies and 58.6% of February babies put off starting school, according to Mediapen’s 2022 look back.

The school entry cutoff moved to January 1 across the 2009 and 2010 school years. The 2009 intake was children born March to December 2002, and the 2010 intake was everyone born in 2003. Mediapen noted that the government had weighed the social cost of those early-birthday kids growing up and having to sort out what to call everyone.

From the 2003 babies on, the default school year and the line match. Before that, a February 1989 baby who started school with the 1988 kids is donggap with the 1989 kids a grade below, and spent twelve years of school as a classmate of the 1988 kids.