Age: Unknown

Gender: Unknown

Personality: A solitary and stubborn dark stranger

Classic Quote: "Stone never changes."

Values: Opposes the virtual world, believes the world should not change

Mission: To avenge its "sacrificed" father, Dr. Light

Physical Characteristics: Similar in appearance to Earth's black cats, allowing Stone to disguise itself as a "black cat" in Spark City. However, Stone's feet are enhanced by its smart part, and its body is surrounded by a mysterious glow.

Character Bio: Stone is a resident of planet Ainia, and its father is Dr. Light, one of the creators of Ainia's virtual world. Many years ago, Dr. Light conducted an experiment to test the method of transferring life between the physical and virtual worlds, using himself as a sample. Due to an accident, Dr. Light's physical body "disappeared" in the real world. While the people of Ainia hailed Dr. Light as a great pioneer, Stone only felt the pain of losing its father to the virtual world. Ainia advocates "the world is always changing," but Stone opposes this, believing that unchangeability is correct. It thinks that the development of the virtual world will only cause the physical world to deteriorate. Over the years, Stone explored both the virtual and physical worlds, trying to uncover the mystery of its father's disappearance until it discovered that its father's mentor also participated in the experiment. However, the mentor's life and memory did not disappear with its father but found a new carrier in the physical world, injected into a highly intelligent robot named Nana, who became the nurturing robot for the mentor's descendant Dot, and accompanied Dot's growth. Stone felt jealous and unfair, believing that the mentor betrayed its father and decided to capture the robot Nana and destroy its information chip to avenge its father.