You Were Supposed to Go Undercover, but You Took Down the Boss’s Wife

[Underworld + undercover cop + urban wish fulfillment + no System + ruthless and decisive + multiple female leads] This is insane! My undercover mission is to take the place of a dead crime boss, sleep in his villa, and spend his money. And the worst part is, nobody told me before I went undercover that I’d need to be a master of every skill under the sun!