The story of Chrono Sword is based on Nordic mythology. There are several main characters who drive the story in Chrono Sword, and Freyr is the most important since she is the player character.
In the mythology, Freyr was a male god with a powerful magic sword. But he gave it to a human as gift, and it caused his death and the end of world in Ragnarok.
In Chrono Sword, Freyr is a female vagabond. Though she lost her memory, she is strong and indomitable will. In the early part of the game, she travels through the fallen world of Aesir to find out who she is, what she had done, and why the world lost the light. This is just the beginning of the story.