From The Rain (빗물에게 들으니) by Heize is a song about gratitude and the impermanence of relationships. The lyrics describe the narrator's relief that there are no problems in her life, and her concern for someone she cares about. Despite her worries, she acknowledges that their relationship might not last forever. The chorus words "Become an endless rain" refer to the narrator's desire to be held and comforted by the person she cares about, but also how certain emotions and memories can stay with us, like, an endless rain. The line "Leave a mark that cannot be easily erased" represents the deep emotional impact that the person has had on her life. Towards the end of the song, Heize talks about how everyone has their "gray clouds" that follow them, even on clear days, and how some memories have hit the heart, leaving an indelible mark. Overall, From The Rain is a song about the impermanence of relationships, gratitude, and the importance of cherishing the moments we have with the people we care about.
