Just as he is about to close the last window of his house, Shiki finds himself at the mercy of the infamous Phantom Thief, a mysterious figure who'd been stealing lots of valuable items and could never be caught. Shiki is about to scream and alert the police when the Thief confesses to stealing everything in order to help his sick mother. Touched, Shiki even hides him beneath some sheets and the two witness a conversation between Shiki's two step brothers: with his biological mother gone, Shiki is forced to stay in his father's house, where he's shunned as the mistress's son. After hearing this, the Thief makes an unexpected offer: he invites Shiki to come with him, then runs off, leaving him stunned.

The next day, Shiki's stepmother discovers her ring had been stolen and, naturally, blames the innocent Shiki for it. They're interrupted by Seomi, the captain of the guards, who announces he will be conducting the investigation. There's one problem, though: Seomi is none other than the Phantom Thief himself!