A gathering between Nai and Ya during their college career made them fall into the memories of the past, and they suddenly discovered that no matter how beautiful the flowers are, they will eventually fall. There is too little happiness along the way, but the pain is always inadvertently magnified and spread infinitely. Everything in the past is blown by the wind and scattered one by one in the depths of the scars that we have never touched. Those green years are still engraved in the hearts of Nai and Ya. They are just constantly confused by the scenery along the way, but they have no time to look back at the road they have traveled. They are all very good, but they have lost those familiar shadows around them forever. Back then, they ignorantly did things they had never experienced before, with unruly temperament, taking advantage of their youth and frivolousness to try to get rid of the shackles that tightly bound them, but they did not realize that the more they broke free, the more they trapped themselves in a cocoon. And what remains now are the fragments left behind by the wasted years. They were very happy because even though they were separated that year and were ignorant, they still didn't know how to lose, and they still encouraged each other to fly far away. Life is really a train, but you have quietly left before you realize it...