As a typical teenage student, Kaito Kuroba frequently finds himself alone due to his father's unexplained absences. However, following his father's mysterious death, Kaito uncovers a shocking secret: his father was actually the notorious International Criminal 1412, also known as the Phantom Thief. Unfortunately, his father's involvement with an unnamed group regarding a mystical stone called the "Pandora Gem" proved to be fatal, as they murdered him for withholding the gem's location. In an effort to stop the group from obtaining the gem, Kaito takes on his father's mantle and becomes the Phantom Thief, determined to locate the gem before it's too late. The only clue he has is that the gem is a doublet, concealed within a larger gem that emits a red glow during a specific comet's passage. This unique gem can only be found in a location devoid of moonlight. Kaito dedicates himself to stealing other precious gems from heavily guarded places with the intention of locating the Pandora Gem, returning the other gems upon the next full moon.