Belgrieve, a retired adventurer who lost his leg in battle, found an abandoned baby in the forest years ago and raised her as his own daughter, Angeline. He trained her in combat and survival, then watched her leave for the capital to become an adventurer. She came back as an S-Rank, the youngest in history, under the title 'Black-Haired Valkyrie.' Now reunited, Belgrieve and Angeline face threats that target both the quiet countryside and the adventurer guilds.