"Kiriya Hakushakuke no Roku Shimai" centers on the Kiriya family, a noble household consisting of six sisters who live in a grand mansion. The story unfolds in a historical fantasy setting, blending elements of drama, mystery, and supernatural intrigue. The sisters—each with distinct personalities and abilities—navigate their lives while uncovering secrets tied to their family’s past and the mysterious circumstances surrounding their parents' disappearance.

The eldest sister, Aya, assumes the role of caretaker, striving to maintain order and protect her siblings. Her practical nature contrasts with the more whimsical and artistic second sister, Haru, who often provides emotional support. The third sister, Sakuya, is studious and reserved, often delving into the family’s archives to uncover hidden truths. The fourth sister, Chidori, is energetic and tomboyish, frequently clashing with the more refined fifth sister, Suzu, who embodies grace and elegance. The youngest, Hatsu, is innocent and curious, often serving as a catalyst for the sisters’ adventures.

The narrative explores the sisters’ efforts to unravel the mysteries of their lineage, including the significance of a peculiar artifact left behind by their parents. This artifact, a key to their family’s legacy, becomes a focal point as external forces, including rival factions and supernatural entities, seek to claim it. The sisters must rely on their unique strengths and bond to protect their home and uncover the truth about their parents’ fate.

Throughout the series, themes of familial loyalty, resilience, and self-discovery are interwoven with moments of tension and emotional depth. The sisters’ interactions and individual growth are central to the story, as they confront both external threats and internal conflicts. The blend of historical aesthetics, supernatural elements, and character-driven drama creates a compelling narrative that balances mystery with heartfelt moments.