Shinmai Maou no Testament

High school student Toujo Basara faces an unexpected upheaval when his eccentric father suddenly remarries, bringing two alluring step-sisters, Mio and Maria, into his home. His new domestic reality is quickly shattered upon discovering their true identities: one is a succubus and the other a newly crowned Demon Lord. This revelation plunges Basara into a supernatural conflict where he is initially expected to enter a pact as their eternal servant, binding him to serve their demonic needs without question. However, a critical error during the ritual inverts the magical agreement, transforming Basara from a subordinate into their master instead. Now burdened with authority he never sought, he must navigate a treacherous path defined by his sisters’ relentless seductive advances and the lethal threats posed by rival demon contractors. To survive this dangerous new existence, Basara must rapidly adapt to his reversed role, mastering the complexities of his contract while defending his unconventional family against enemies determined to exploit their vulnerability.