Shio Kōbe is depicted as a kind-hearted, naïve, and innocent young girl who knows little about the world beyond the apartment where she lives. She takes her role at home seriously, striving to do her best to look after their shared space while Satō Matsuzaka is away at school or work. Shio is always overjoyed when Satō returns, greeting her warmly and cherishing the time they spend together. She genuinely loves and trusts Satō, believing that they must remain together, as being apart would leave them both broken and incomplete.

Though Shio’s interactions with others are limited, she consistently displays the same warmth and sincerity toward them, qualities that often attract affection or even obsession. She is frequently described with terms like “angel,” “light,” or “the moon,” symbolizing the rare purity and almost ethereal nature of her personality. However, Shio herself rejects the idea of being entirely pure, as shown when she bluntly tells Taiyō Mitsuboshi that she is not as pure as others perceive her to be.

Shio Kōbe is an eight-year-old girl with dark blue hair, typically styled in two messy pigtails. When her hair is worn down, it reaches the nape of her neck. She has large, expressive blue eyes that add to her innocent and gentle appearance.

Shio is most often seen wearing a sailor-style school uniform consisting of a light blue long-sleeved shirt, a striped blue and black bow tie, and a blue plaid skirt. Since she rarely leaves the apartment, she is almost never shown wearing shoes, though she usually wears black socks that reach just below her knees.

Shio Kōbe was born into a troubled household, with her mother, Yūna Kōbe, expressing sorrow that Shio had entered such a cruel world marked by an abusive father. Shio became a symbol of hope for both Yūna and her older brother, Asahi Kōbe. At one point, Asahi encouraged their mother to flee with Shio to escape their father’s violence, vowing to stay behind to prevent pursuit and promising to reunite with them.

Yūna and Shio eventually found a place to settle, but life remained difficult as Yūna struggled with poverty and emotional instability. Shio, sensing her mother’s despair, tried to cheer her up, but her efforts were often in vain. Yūna, fearful of being found by Shio’s father, forbade Shio from leaving the house and reacted harshly when she disobeyed, despite Shio’s innocent intentions.

As Yūna’s mental state deteriorated, she became increasingly unstable. After a near-accident where Shio was almost struck by a truck, Yūna’s despair culminated in her abandoning Shio during a rainy night, pushing her into an alley and telling her she no longer needed her. It was then that Satō Matsuzaka found Shio and took her in. Shio, seeing Satō as someone with an “empty, but not broken, jar” of a heart, latched onto her as a new source of love, causing her to suppress memories of her previous life.

From then on, Shio lived with Satō in their apartment, spending most days alone while Satō attended school and work. After one attempt to leave the apartment, during which she encountered Taiyō Mitsuboshi and hallucinated visions of her mother, Satō installed a lock on the door to prevent Shio from leaving again. Shio remained unaware that Asahi was desperately searching for her.

In the story’s climax, Shio sustained minor injuries after embracing Satō and falling from the rooftop together. Satō died shielding Shio from the impact. Following the incident, Shio keeps Satō’s wedding ring and hair ribbon as keepsakes, believing she has been “reborn” as Satō and convinced that Satō will one day be reborn as well, an unsettling declaration that deeply shocks Asahi.

Satō Matsuzaka
Shio cares deeply for Satō and sincerely loves her, remaining largely unaware of the dark actions Satō commits to protect their life together. Confined to their apartment, Shio gradually forgets her life before meeting Satō, with only fleeting and haunting visions of her mother. After Satō murders Shōko Hida, Shio demands the truth, urging Satō to share everything so they can face it together. Shio views herself as Satō’s equal and wishes to share in her burdens, demonstrating unwavering devotion. Even after learning of Satō’s crimes, Shio stands by her side, and the two hold a makeshift wedding ceremony, exchanging vows and rings. Shio’s loyalty persists during their final confrontation with Asahi, as she stops him from harming Satō and chooses to stay with her rather than return to her family.

Yūna Kōbe
Shio is Yūna’s daughter. Yūna once saw Shio as a pure and innocent presence, much like herself as a child, though she regarded Shio as more clingy than Asahi. Shio’s memories of her mother become fragmented, often manifesting as hallucinations during times of distress.

Asahi Kōbe
Asahi is Shio’s older brother, eight years her senior. After helping their mother escape their abusive father with Shio, Asahi remained behind to protect them and intended to reunite when it was safe. Following Shio’s disappearance, Asahi becomes desperate to find her, viewing Shio as the light that holds their family together. He deeply resents Satō for taking Shio away and considers her smile the “moon”, a symbol of hope and happiness in his life.

Taiyō Mitsuboshi
Shio’s only direct encounter with Taiyō occurs after she briefly escapes the apartment. Taiyō, obsessed with the idea that Shio can “purify” him, asks her to heal his emotional wounds. Shio, confused, simply pats his head. The interaction is cut short when thugs attack Taiyō, causing Shio to hallucinate and faint. Satō intervenes, kills the attackers, and takes Shio home. Despite the brief encounter, Taiyō remains fixated on Shio and keeps missing person flyers of her.