In this city, there is a legend.
It is said that all those who have obtained all twelve stars called "Ambitious" can have their ambitions granted.
And there is one of the people pursuing the "Ambitious" will appear in Sahoro City tonight――
"A Letter of Warning
Tonight, I will take the beautiful starry sky of this city.
Miss Arte, the phantom thief."
The main character, Nezu Mikage, happens to be at the crime scene.
By chance, he discovers the phantom thief true identity.
He can tell that the phantom thief is the ojousama of his class, Kaguya Arise.
She has to eliminate every possibility of being found out by those around her. So――
I will steal... your heart and your sigh.
Kaguya, who didn't want her identity to be exposed, tried to draw Mikage into the Phantom Thief Club, which she had created to fulfil her ambitions, but... it does not seem to be working well.
That's when the orphanage, where Mikage was born and raised, fell into a predicament.
Miss Arte, who appears there, expose the hidden "truth" and easily protected the orphanage.
"Is it different from a thief?"
"Yes, steal the hearts of those who see it, and steal everyone's sigh. That's the Phantom Thief."
"Fine. I'll help you and your 'ambitions'."
'Miss Arte the Phantom Thief' and 'Midnight the Phantom Thief'
Just as the two phantom thieves joined forces, the curtain rose on the hidden "truth" in the night of Sahoro City――