In high school, the academic male protagonist regarded the academic scumbag female protagonist as a "variable" to study, but involved himself in it; in college, they fell in love and killed each other across the mobile phone screen, and worked hard to shine in their respective fields; after work, they reunited after a long absence, and they lost their youthful feelings and reaffirmed that each other is an irreplaceable "constant" in the torrent of reality.
