'' Everyone has a dark past, that turns out they want to revenge like me '' Black Foxes,a worldwide know group of thieves that never been captured in this past 3 years. They consist of 5 man but to the truth is they're all women who disguised themselves man in their missions. Thieves that every police should captured especially Thief X, the Ace, the most dangerous among the 5 of them. Her name is Alexis, a girl who known to be the sweet, caring and silent type of women but has most darkest past among the group. Her family was killed by unknown group of thieves or assasins because of one thing, the Burnsworth's treasure that even Alexis forgotten because of that traumatic experience. She trained for a long time not be the weak her but to be the strong her now that become the most dangerous and legendary thief at this time. No one knows her weaknesses but there's one thing, Her childhood friend namely Issei Sato. She's happy there her childhood friend has come back but then he become a detective and want to capture the Black Foxes especially Thief X, her to be exact. A love between a thief and a detective is forbidden