In the summer when I was seventeen, the cicadas were chirping noisily and the air was hot and humid. In Lin Yang's world there are only endless test papers and the monotonous scenery outside the window. Until that day, a young man named Chen Yu, like an unexpected mint-colored shimmer, penetrated the dense summer shade and shined into her dull youth. With his youthful spirit and a little bit of imperceptible tenderness, he made her boring black and white world tinged with exciting colors for the first time. This is a story about secret love, growth and two-way running. It records the most innocent school time hidden in the wind, textbooks and heartbeats.