I remember there is a feeling called "You stay with me for a while, and I will miss you forever." Every time I see this sentence, that person and that thing always come to mind like a dream. Whether it's love, family or friendship, having someone you can care about for the rest of your life is a blessing, a kind of happiness, which invisibly turns into a kind of courage and a kind of motivation to guide you forward. This story tells a unique relationship between teacher and student, both teacher and friend. They transcended the most ordinary teachers and students, but they also stopped at the deepest friendship. In class, they are teachers and students; in private, they are very good friends. To him, she was just an ordinary student who wanted to make progress; to her, he was his guide on the road ahead, the sail for his voyage, and the light that lit up the alley late at night. He was more like a belief, supporting himself and walking forward. College entrance examination, university. Faced with this new starting point, she hesitated. The farthest distance in the world is that it is so close yet so far away. I want to see you, but after all I am missing that identity. If the fate of this life is limited to standing in the distance, silently watching your leaving figure... There will be countless turns in life, but this time, she couldn't help herself for a moment, took over the heavy expectations, and stepped out of the school. At that moment, she burst into tears, and all her previous persistence turned into bubbles. In the inner struggle, he knew that behind that goodbye was her heartbreaking pain. The man who taught her courage, gave her warmth, and even changed her destiny, the relationship between them finally...