悪ノ大罪 ヴェノマニア公の狂気

Book one of the Aku no Taizai series. Duke Sateriasis Venomania, who, in his childhood, had been mocked and taunted by others. In adulthood, he made a deal with the devil to have an irresistible charisma to women. As a result, women began flocking to his mansion's basement to create a harem for him. One of these women happened to be the one who "made him for a fool." This girl, now a young woman, was his childhood friend, Gumina Glassred.