"This may be the last time I see you all. My dad and mom are both sick and my mom is in the ICU, so I'll have to look after them and won't be able to come anymore," Cao Feng told her class at Yuwang Secondary School in Huaiyuan county, Anhui Province, the state-run Guangming Daily reported.

The next day, in her homeroom teacher's office, Cao said her mother wanted someone by her side in the ICU. "My dad has liver cancer, but for the family's sake he has to drive a ride-hailing car 12 hours a day, and his legs are swollen when he gets home," she said.

Her older siblings were all earning money, she added, and "the only thing I can do is be with her."

Classmates then filed into the office and tipped an envelope of coins and banknotes onto the desk. One had sold an online gaming account, while others brought Ultraman cards collected since childhood, a sports star's jersey, a favorite singer's album and a barely worn pair of shoes bought for a physical education exam, all to be sold for her family.

As Cao left the campus, the entire school, teachers included, lined the corridors of the classroom building, chanting "Keep going, Cao Feng!" again and again.

A video of her farewell, posted on Oct. 22 by Douyin creator Liangtian, who has nearly 23 million followers, had drawn more than 12 million likes and 250,000 comments on the platform by Nov. 3.

Cao Feng with her mother in intensive care. Photo courtesy of Douyin

Cao is the youngest of five children, and her 47-year-old mother has generalized myasthenia gravis, a chronic condition that causes muscle weakness, along with a tumor of the thymus gland, the South China Morning Post reported.

Her mother was admitted to intensive care in Shanghai with respiratory failure, and ICU treatment costs 10,000 yuan ($1,500) a day, the newspaper said.

Her homeroom teacher, Li Chengjie, told the Anhui news site Dawan News that Cao, a disciplined student who was consistently near the top of her class and won a school scholarship every year, had gone days without handing in homework during the school break. After patient questioning, she explained that her mother had been ill for years and needed constant care, Li said.

Cui Miaomiao, the school's head of student affairs, told the news site that teachers contact Cao every day to follow her studies, daily life and mental health, and that the school will help her complete late registration in December for the gaokao, China's national college entrance exam.

The school has also waived all of Cao's fees for her final year and sent her a hardship payment, while the Huaiyuan county education bureau has granted her a national high school student grant for the autumn semester, Guangming Daily reported. Cao planned to sit the gaokao in 2027.

The gaokao, the world's largest college entrance exam, had 12.9 million registered candidates this year, according to the Ministry of Education.