Zhou Zhi didn't know what kind of existence he was in Si Bei's heart. It wasn't until he opened Si Bei's iron box covered with traces of time and saw his name on every piece of Si Bei's diary that Zhou Zhi had the answer.
Si Bei thought that the first time she and Zhou Zhi met was in her freshman year of high school. During the 100-day swearing-in ceremony in her senior year, she saw Zhou Zhi in military uniform in front of the teaching building; but the first time Zhou Zhi saw her was when she was studying in isolation a year ago and she sang in front of everyone.
[The male and female protagonists are the same age, both clean]
Intention: secret love