Synopsis

Professor Agasa took the Detective Boys – Genta, Ayumi, Mitsuhiko, Ai, and Ayumi – to the Beika Department Store. While there, a customer near the stairs stabbed Chef Hosogoe, the head chef of the restaurant on the top floor. Inspector Megure questioned the children, all of whom claimed to have seen the assailant, but their accounts were inconsistent. Determined to unravel the mystery, the Detective Boys explored the store's many levels, seeking to understand why their observations differed.