Xiao Wu, A Tu, and Jack, who grew up together, retake their high school entrance exams at 17, just before turning 18. All three experience their first love. Xiao Wu and A Tu participate in a car-themed social event and both develop feelings for Aya, though they keep their feelings hidden. Xiao Wu, seeing himself attending a third-rate school, decides to drop out and pursue Aya openly. Their romance is finally revealed, but they can’t escape the lessons of growing up as Xiao Wu fulfills the mandatory military service. Aya and A Tu are drawn to each other, disregarding their friendship. At 17, their relationship abruptly ends in pain and loss.