Su Xia, a girl who transferred from high school, met some people in this beautiful time. They may be lively and cheerful, they may be bohemian, they may be calm and reserved, they may be introverted and shy... No matter what, they all have their own unique flavor. They go hand in hand with Su Xia, but who understands Su Xia and who will accompany Su Xia to the end? Has anyone among them ever truly entered Su Xia's heart? Or are they all just passers-by? Who will Su Xia say "Thank you for walking by me."?