Was it ”academic stress”? ... Three high school students die together in Busan, South Korea

In Busan, South Korea, three high school students who attended the same school died together. They left behind suicide notes stating that they were "under a lot of stress from their studies and the burden of choosing their future careers."
On the 22nd, according to the police and the Korean daily newspaper "Chosun Ilbo," a suicide note was found at the scene where three female second-year students at a certain high school in Busan died the previous day (21st).
The suicide note contained the following content: "As I approach my third year of high school, the stress of my studies and the burden of my future is heavy." However, there was no mention of violence at school or anything else, and the girls' "The Body" also reported that they had been assaulted.
No traces of the body were found. The girls were found lying in a flowerbed at an apartment building in Haeundae-gu, Busan, at around 1:39 a.m. on the 21st and were taken to the hospital, but all three died.
The apartment's CCTV footage captured the three entering the apartment at around 11:43 pm on the 20th, getting on the elevator and getting off on the 20th floor.
It is known that none of them lived in the apartment. After this incident, the Busan Metropolitan Office of Education set up a joint task force to investigate the truth behind the incident.
The Busan Metropolitan Office of Education also convened a crisis management committee to hold an emergency countermeasure meeting led by the superintendent of education, and announced that it would carry out a special inspection of the school.
■Main consultation services listed on the Ministry of Health, Labor and Welfare website to prevent suicide ●Mental health consultation hotline: 0570-064-556
●Yorisoi Hotline: 0120-279-338, From Iwate, Miyagi, and Fukushima prefectures: 0120-279-226
● Lifeline: 0570-783-556