Long Yi is a junior student in Tsinghua University. He used to sell used goods on mobile application to make extra money. Once, he noticed a senior selling her quits online by chance, and he thought it might be a good business opportunities. In the graduation season of this year, Long bought some quilts from senior students and started to sell them. Unexpectedly, these used quilts became popular among the students, and Long can even made over 10,000 yuan a day.