Watashi, Senetsu nagara Tensai desu no: Sono Reijou wa Hibon na Suiriryoku de Ai no Kyojitsu wo Kanpa Suru

Elizabeth has been called the daughter of the fallen since the disappearance of her father, the patriarch of her family. But what's this?! In order to restore her family's fortunes, she takes over her father's detective agency! She assigns Will, her father's butler, to be her assistant detective, and she now calls herself the Lady Detective, who solves every case with elegance! Now, Elizabeth, the Lady Detective, and Will, the detective assistant, are ready to solve all kinds of cases in the capital city! Love and lust lurk behind every incident... Now begins an exquisite mystery with our key detectives! (Source: MangaPlaza)