Before her appears a young man named Orion who calls himself a spirit. With his guidance, the heroine begins to search for her lost memories before others can find out she has forgotten them. Gradually, relationships with people around her begin to materialize... childhood friends, respected seniors, and even lovers whose names and faces she no longer knows. Without her memories, though she is keenly aware of their feelings toward her, she is unable to respond to them in kind...
As fragments of memories come back to her and unexpected crises befall her, the story grows increasingly complex as it pulls our heroine in deeper and deeper. What answer lies just beyond the memories she has lost?