Getting Closer at N Times the Speed

Lin Yu'en is having PE class on the sports field when a boy runs past her and smiles back over his shoulder. A warm current seems to flow through her whole body. She freezes, standing right there until the boy has run back to the classroom, and only then comes back to her senses.

Theme: A sheet of scratch paper holds not only complicated formulas, but also the name of the person most important to me.