From a young age, Yumi was deeply immersed in books, cherishing her role as a library committee member. Yet, she gradually begins to sense the hidden dangers lurking within her daily life. One day, she becomes troubled by upperclassmen causing a disturbance in the library. Among them is one particularly malicious individual whose cruel behavior frightens her. Despite her fear, Yumi chooses to stand up, feeling it's her responsibility. That single step becomes the turning point that drastically changes her life.