A school romance between a young bubbly girl who encounters a math genius with a high IQ and a low EQ, but he is a little more than that as he hides another him. When 17-year-old Lin Yuan gave her heart to her math teacher, she found only heartbreak. In her whirlwind journey into adulthood, she learned to let go of an impossible love and say goodbye to the friends of her past. Yet she bears the memories of heartbreak, and finds herself unable to love again, until she meets the intellectual Xiao En, another handsome, talented math teacher. Can lightning really strike twice, or is there a deeper mystery? Lin Yuan finds herself entranced by his genius and charms, and drawn deeper and deeper into a new yet familiar romance.