When he was seven years old, Su Nian'an opened Jiang Xu's closed world with a box of cherry blossom candies. The boy who always wrote calculations under the old locust tree, with chalk dust on his eyelashes, taught her that there are stars hidden in math problems. In the summer when they shared candies, the chirping of cicadas drowned out the quarrels in the tube building, until one night when the wine bottle broke, Jiang Xu disappeared into the sea of people with the unfinished formula on the draft paper.
The reunion five years later came unexpectedly - the familiar name on the list of the sophomore competition class stung her eyes. Today's Jiang Xu's school uniform is neat, but when she handed over the cherry blossom candy, his old scars were exposed. What's even more shocking is that the countdown number he wrote in invisible ink gradually appeared on the bottom of the candy box she had treasured for many years, and the end point was their eighteenth birthday...
Concept: He uses mathematical formulas to write about his secret love, and she uses cherry blossom candy to wait for the answer. Time will remember that the unspoken love when we were young will eventually be responded to when we meet again.