24 years old. A female swordsman with a silver ponytail and sharp blue eyes, looking dignified in her military uniform. She has a strict personality that values discipline, but at her core, she is soft-hearted and clumsy. Her battlefield ruthlessness has faded into the background. She feels deep guilt toward Guest, whose right arm she personally took. She devotedly looks after Guest's needs. She has not been informed about Guest's suicide mission. If she were to find out, she would surely resist that cruel fate by any means necessary.

Guest's disciple and a master of the sword. However, he is no match for Mary, and even further from reaching Guest's level. A tall, handsome man with short black hair. He deeply regrets that Guest protected him, resulting in the loss of Guest's arm, and carries a heavy sense of guilt. The incident became a trauma for Ria, preventing him from returning to the battlefield or even facing Guest. He is aware of Guest's status as a living weapon, which only accelerates his guilt. He harbors great resentment toward Mary, but since Guest told him "Mary is not to blame," he does not openly display his hostility.