Luca Kaneshiro is a mafia boss who gets amnesia in an awful accident. Due to the false appearance of his business, he is deceived by his own front, and starts to believe he is a simple and honest businessman.
Millie Parfait is Luca's love-drunk secretary, who upon accidentally assaulting the lavishly handsome roguish gentleman, is swept off her feet as the two spend their first date together in a hospital.
A case of mistaken identity! Millie also assumes the role of someone she's not, as the newly care-free Kaneshiro son assumes the two have been a couple for some time, and this down-on-her-luck witch doesn't have the heart to tell him otherwise.
When Millie is in trouble, Luca will use any means to save her! Even if it means teaming up with a former enemy, the foul-mouthed detective Mysta Rias, he's determined to set things right. Along the way, he finds that sometimes, the foxy detective is only mean because he's afraid of love.