When Shio was born, Yūna Kōbe (Shio's mother) felt sorry for her because she was born into a cruel world with her abusive father. However, Asahi Kōbe (Shio's older brother) suggested to his mother that they should work hard to protect her, and Shio soon became a ray of hope for the two of them. At some point, Asahi urged his mother to run away with Shio and he would stay behind so that their father wouldn't try to find them. He promised to return to his mother and Shio, and made a vow. Eventually, Shio's mother found a place for them to settle in, waiting until the day Asahi returned, but struggled to keep up with paying rent because of her inability to get a well-paying job. Shio was starting to notice that her mother was slowly breaking apart and tried her best to cheer her up, however Shio's attempts at comforting her mother were often futile, as her mother fluctuated between many emotional extremes due to her past and current circumstances. Because of her mother's fear that her father would find them again, Shio's mother forbade Shio from leaving the house and got angry whenever Shio disobeyed her, despite Shio's intentions to help her mother feel better (such as going outside to pick a flower for her). As her mother's state was gradually diminishing waiting for Asahi to return so that they could be happy, Shio begged her mother to take her outside so that she could find something to help fix her, but almost got hit by truck because of it. Shio was immediately brought back home and was scolded for wanting to go outside. For the first time in her life, Shio's mother slapped her, but quickly broke down due to the resemblance between her actions and her husband's abuse.Soon after that incident, Shio's mother decided to take Shio outside again during a rainy night, and pushed Shio into an alleyway. Despite Shio begging for forgiveness and promising to be obedient, Shio's mother stated that she no longer needed her, and left Shio by herself. Then it was at that moment that Shio encountered Satō Matsuzaka who then took her to The Painter's apartment. There, the Painter attempts to strangle an unconscious Shio for his own selfish reasons but is killed by Satou instead. Shio noticed that Satou's "jar was empty, but not broken" because she still believed in something, unlike her mother's "jar", which Shio believed was broken. This caused Shio to forget everything that happened, and the reason is she has a hard time remembering her life before Satō. Shio lived with Satō in their apartment and is often left alone for most of the day because of Satou's school and work obligations. She is perfectly capable of leaving the apartment and does one night which results in her running into Taiyō Mitsuboshi and later having hallucinations of her mother's figure in the park. After that incident, Satou installs a lock from the outside and does not leave again on her own will due to Satou telling her about the dangers of the outside world. She was unaware of the fact that Asahi is searching for her. "I'm Shio Kobe."