My younger sister, Minju, who is one year younger than me, already got her adult license last winter.
Eighteen-year-old Minju gained the right to vote in January of this year, can open a bank account without a guardian, and can even get a driver's license if she wants.
As an adult, Minju moves to a residence provided by the state within six months and becomes independent.
When he was young, he thought his younger sister, who was so smart and lovable, was so special, but when Minju, who was always smart, became an adult before him, he felt worse than he thought.
The biggest problem is polite speech.
Isn't a younger sister meant to be teased or used?


'I wiped away so many tears and snot, and you're telling me to use polite language towards this little thing!'
Just imagining it made my stomach boil.
However, it is a serious misdemeanor for a minor to speak informally to an adult.
I once read an article about a family where the eldest son punched his younger brother in the face after he became an adult, saying he couldn't stand it anymore.
After raising his voice repeatedly, the seizure button was finally pressed.
Minsu even swore at a stranger whose face he didn't even know, saying, "How much of a jerk must you be for your younger brother to become an adult first?"
When Minju declared that she would challenge for adult certification early, Minsu was instantly reminded of that rascal.
A sense of foreboding came over me that this might not be someone else's business.
--- From "The Bluebird's Sky"

Dong-ha took his place, pushed by the cries of the gaori.
Junwoo had a habit of letting out an inexplicable exclamation of "Ah-ah! Gaori" whenever he was in a good mood, and the other two who hung out with Junwoo also naturally got used to saying that, and they naturally became the Gaori Trio.
The Gaoris consistently ranked in the top 10 in the entire school.
Of course, at the end.
Of course, my scores in Korean, English, math, and science were low, but no one cared about that.
The university selected the AI's possible admissions based on its academic record and college entrance exam scores.
There was a bigger problem.
6th period personality area.
If you mess up the 6th period, everything will be for nothing.
Even if you get perfect scores in other subjects, it is impossible to advance to higher education.
One out from adult verification.
We have to look forward to next year.

After the CSAT is over, the entrance exam results for each high school are announced.
A school with few dropouts in the 6th period is a prestigious school.
The portal was flooded with articles analyzing the increase and decrease in dropouts that year and their regional distribution.
The number of dropouts was an indicator of the health of society.
In years with a particularly high number of dropouts, both academics and the media were busy looking back on the past 20 years, wondering if there had been any major incidents or accidents in the year they were born, or if there had been any events that might have caused collective shock during their adolescence.

Given these circumstances, as the college entrance exam approaches, schools are on high alert to prepare countermeasures for students who fail to pass the 6th period cutoff score in mock exams.
Schools that produced a particularly large number of underage students received ethical criticism from the public.
It is the mission of educational institutions to cultivate healthy citizens who will take responsibility for the future of the country, but they have failed to do so.
Principals and foundation chairmen were on edge every entrance exam season, worried that the arrows of criticism might be aimed at them.
Who will tarnish the honor of our alma mater this year?
Gaoripa failed to pass the cutoff line once every three times he took the mock exam.
Even the students who had never cared about their grades while growing up were preoccupied with the subtle pressure from their teachers.

'Somehow it'll work out!'
The unfounded optimism I had held up as my life philosophy whenever something unpleasant happened to me became less and less comforting.
This is because Gaori also knew very well (because they didn't say anything) that things that were put off for a while, thinking that they would somehow work out, rarely turned out as well as expected.
I don't understand why life only likes the laws of cause and effect and loathes romantic notions like getting rich quick or the blessings of fate.
The teachers who met the eyes of the students during every class let out a sigh from the depths of their hearts.
Now, the atmosphere has become such that even the most shameless of gaolis cannot ignore the situation.
--- From "6th Period Personality Area"

Zone 4 is the star of the underage.
Anyone who is not recognized as an adult when they reach adulthood will not be granted citizenship on Earth.
What made Zone 4 different from Zone 3 was that there was freedom there.
The state provided only the most basic necessities for minors, so they had to work for everything else.
They could also mine minerals, but it was not mandatory.
The mined minerals were converted into coins and circulated as currency in the three districts.
As long as you had coins, you could buy as many items as you wanted from Earth.
You can even get adult certification.
Mining minerals was a physically demanding job, so most of the young people who endured the harsh labor would quickly become old.
Those who did not work had nothing to do but slowly wither away.
The amount of coins required for adult certification varied depending on the 6th period score, so those who wanted to return quickly endured back-breaking, extreme labor and quickly broke away from their former, extravagant selves.


The maintenance costs of Zone 4 were covered by tourism revenue.
The Galaxy Train to Zone 4 was the best tourist product with high added value.
Parents who had sent their minor children away were the main customers.
Parents with a peculiar constitution who could not let go of their attachment to their children even after taking Sanitas, or who refused to take medicine despite the pain that was pouring in, visited District 4 periodically, spending a large amount of money.
It was also significant that the wealthier the class, the more likely they were to have minor children.
There was even a case where a parent, who had spent all of their savings to secure a comfortable old age for their child, ended their own life after a final visit.
When these occasional incidents were reported in the social media, ticket sales temporarily plummeted that week.
But that was it.
Soon, train tickets were selling out at lightning speed again as parents missed their children.

--- From "The Fifth Industrial Revolution"