Lux, a former prince of an empire named Arcadia that was overthrown via a rebellion five years earlier, accidentally trespasses in a female dormitory's bathing area, sees the kingdom's new princess Lisesharte naked, incurring her wrath. Lisesharte then challenges Lux to a Drag-Ride duel. Drag-Rides are ancient armored mechanical weapons that have been excavated from ruins all around the world. Lux used to be called the strongest Drag-Knight, but now he's known as the "undefeated weakest" Drag-Knight because he will absolutely not attack in battle. After his duel with Lisesharte, Lux ends up attending the female-only academy that trains royals to be Drag-Knights. ___ **Compositor:** [Watanabe Itsuki](https://mangadex.org/author/eb66b421-fb65-4aca-95d0-e6d29fc3ba78) **Character Designer:** [Kasuga Ayumu](https://mangadex.org/author/82c4316a-f764-4e20-a563-7e6dcfee6ac9)

Two years after his father's death, a girl in a wheelchair suddenly appears and becomes Tsuzuki Ui's classmate. He soon learns that she is a detective from the wealthiest family in Japan, and that it is not the first time they have met each other. She came to investigate Ui's father's death — an alleged suicide — and for some reason, she strongly suspects Ui's little sister Haruka…