More than 50 people are now known to have died and 252, mostly children, an presumed dead in the upturned hull of the stricken vessel that capsized off the southwestern tip of the Korean Peninsula on Wednesday.
Since then, Kim and hundreds of other relatives have spent 24 hours a day waiting helplessly for news in makeshift accommodation at a gymnasium in the port city of Jindo, the centre of the rescue operation.
They live and grieve together, packed into the floor space on narrow, thin mattresses, taking to a communal microphone to vent their hopes and their anger at government officials over the seemingly slow pace of the rescue and patchy information.
Kim's brother, Dong-hyup, was one of 339 pupils and teachers from Danwon High School on an annual outing to the subtropical island of Jeju, making up most of the 476 passengers and crew.
"He called me at 8 a.m., saying the ship is sinking. Then I lost him," Kim, a 22-year-old student, told Reuters.
The Sewol ferry took more than two hours to sink in calm waters on a well-travelled 400 km (300-mile) route from the mainland South Korean port of Incheon to Jeju, a journey of 13-and-a-half hours.
HOPE, ANGER AND TRAGEDY
The gym has become a focal point for anger and fading hope.
It was also the scene of one more tragic death. Kang Min-gyu, 52, the Vice Principal of Danwon High School, went missing on Thursday and was later found hanged with his belt from a pine tree outside the gymnasium.
Kang left a heart-rending two-page suicide note that was partly released by police in which he said he could not live while the fate of 200 others was unknown.
"Burn my body and scatter my ashes at the site of the sunken ferry," he wrote. "Perhaps I can become a teacher for the missing students in my next life."
Professional care is available on site, there is free Internet and medicines as well as shampoo and soap, but South Korean officials have struggled to cope with the overwhelming tragedy.
Officials took DNA swabs from relatives on Saturday, adding to the foreboding that what had been billed as a rescue mission has become an operation to recover and identify bodies.
"It is a group trauma, not just for parents here but for people across the country. It's not going to be over in one or two months. It is leaving a big scar," said a 48-year-old member of a team of counsellors at the gym, surnamed Yoon.
She declined to give her full name. Many Koreans often do not wish to see their full names used in media commenting on sensitive issues.
There's no escape from the tragedy. Endless TV news and footage from the rescue is played on four huge television screens that relay information to the hundreds grieving inside the gym.
When relatives obtained underwater footage of the rescue taking place in the murky, tidal waters around the Sewol after divers said they had seen bodies, coastguard officials were jeered by those watching.
President Park Geun-hye was heckled by some when she visited the site on Thursday, a rare occurrence in a hierarchical country where respect for authority still counts for a lot.
The microphone set up on a stage is now used more to give voice to frustration and anger than for expressing any hope, and channels the rising emotions of those waiting largely in fear.
"It will be a miracle if they are alive. I just want to hug my child's body," a father said from the stage to applause from other waiting relatives.
At other times, they grab at the collars of the coastguards trying to explain that they are doing the best to find the missing.
Often they just weep, looking at pictures of lost sons or daughters on their cellphones.
"What does everything here mean?" Kang Dae-hyun, whose son Hyuck is missing, kept murmuring to himself. "It's so worthless."