The Dilettante 

Stay until you're drunk on me. One day, top counterterrorism agent Hana Lee receives news of her twin brother's passing. Unable to accept the death of her only living relative, she sets out to uncover the truth. Along the way, she gets tangled up with the mysterious Eunseong Yoo and the cold-blooded mafia boss, Giulio Parenti. (Source: Manta) Note: Includes one extra chapter.