Lili Hoshizawa, a 13-year-old girl, takes on the guise of "Spica" to solve criminal cases before law enforcement can catch up. Identifying herself with a star emblem, Spica remains anonymous but is known for her exceptional problem-solving skills. In her regular life, Lili enjoys athletics and helps with her mum's fortune-telling business called "Fortune Teller Spica," using her talents in astrology to analyze clients’ horoscopes.
However, Lili faces a new challenge when her childhood companion, Hiromi Oikawa, returns from America with a background in criminal psychology. Hiromi's return creates a fresh nemesis for Lili's crime-solving and astrological abilities. Lili must remain focused and not let this distract her from solving the cases that require the Spica stamp of approval.
