Shion no Ou tells the story of a young girl by the name of Ishiwatari Shion . At the age of 4, Shion's parents were murdered at their house. The police didn't find anything at the crime scene that might lead them to the murderer apart from a shougi board upon which the pieces were lined up in an orderly fashion. Shion was not harmed even though she was at the house at the time of the murder but the shock of seeing her parents lying dead in a pool of blood resulted in the loss of her voice. The Ishiwatari neighbours and close friends, the Yasuoka family (made up of Yasuoka Shinji and his wife Sachiko) adopted Shion after the murder and raised her as their own daughter and so she was renamed Yasuoka Shion since then. Shinji is a professional Shogi player and during the years that passed after the murder, he taught Shion how to play shogi. Shion was a natural at playing shogi. She learned the game very quickly and mastered it at an early age. She rose quickly in the ranks of the game and became a genius professional player just like her new father. The story is about Shion's life 8 years after the murder and how her chosen path as a professional shogi player might one day lead to finding her parents' murderer.