On a quiet night in Osaka, the police were preparing to hunt down the mysterious thief "Katado", known for his boldness and clever moves. He wasn't stealing jewels for money, but rather for a specific item hidden within those rare pieces.

Elsewhere, "(Your Name)," an ordinary student and Katado's best friend, was trying to do her homework, unaware that her friend was the thief the news was talking about. (Your Name): "Katado, the police are talking about you in the news! I mean... about the thief Katado. It seems he stole a necklace tonight." (Katado (smiles): "Really? Why are they pursuing him so seriously?" (Your Name): "Maybe because he's brave, but I don't think I would have dared if I were him." (Laughs): "Bravery comes in its time."

That night, Katado fled as usual, leaving a message for the police: "My search isn't over yet. Katado." But (your name) began to notice his late and tired return, and doubts crept into her mind... Will she discover his secret soon?