In the city of Sahoro…

A legend has long been told.
Whoever gathers all twelve stars known as the “Ambitious” is said to be able to fulfill any ambition…
And tonight, once again, someone in pursuit of that legend appears on the streets of Sahoro…

“Calling Card:
Tonight, I’ll take this city’s beautiful night sky.
Phantom Thief Miss Arte”

The protagonist, Mikage Nezu, happens to be at the scene of one of Phantom Thief Miss Arte’s heists.
Through an unexpected turn of events, he realizes that the thief is none other than the young lady in his class, Kaguya Arise.

“I have to eliminate even the slightest chance of anyone finding out. So…
I’ll steal your heart… and your breath.”

Determined to keep her identity a secret, Kaguya tries to recruit Mikage into the Phantom Thief Club she founded to fulfill her own ambition, but things don’t go quite as planned.

Then, the orphanage where Mikage was raised falls into crisis.
Miss Arte appears, exposes the hidden truth, and effortlessly saves the orphanage.
Elegantly and brilliantly.

“So you’re saying you’re different from an ordinary thief?”

“Yes. Steal the hearts of those who witness you, then steal the breath of everyone else. That’s what phantom thieves do.”

Without question, Miss Arte steals away both Mikage’s heart and his breath.

“All right. I’m in. I’ll lend you a hand… with this ‘ambition’ of yours.”

When Phantom Thief Miss Arte and Phantom Thief Midnight join forces, the curtain rises on the truth concealed beneath Sahoro’s veil of night…