Tong Zhi, a senior girl in the veterinarian department, has a crush on Gu Bin, a boy in the agricultural department from Taipei. She never has the courage to confess openly, instead opting to use letters that have never been sent for over four years. As she approaches graduation, an unexpected mailing makes Gu Bin misunderstand her intentions, making him think that she likes his good friend instead. As a result, her life falls into chaos. It turns out that in this story, she is not the only one who holds secrets and cannot confess. Can she succeed in having her true feelings heard?