As an elf, Frieren once teamed up with the Hero party of humans to fight against a demon king. This battle lasted ten years, and all of them created many memories with each other. As elves live thousands of years, for Frieren, it’s just a moment, and she does not emotionally attach to them. After she returned to her usual life, she realized that something changed in her. After her few human friends passed away, she realised that those moments meant a lot to her, and then she began her new journey of growing emotionally with others.