The Testament of Sister New Devil Storm!

High school student Toujo Basara never expected his ordinary life to take such a bizarre turn. When his father suddenly announces plans to remarry, Basara is initially hesitant about the abrupt change. However, any reservations he holds quickly fade upon meeting his new family members: two breathtakingly beautiful step-sisters who harbor an extraordinary secret. Far from being typical teenagers, both girls are deeply connected to a powerful demon clan. Mio Naruse is, in fact, a Demon Lord, while her constant companion, Maria Naruse, serves as her devoted succubus attendant. Thrust into this supernatural dynamic, Basara must rapidly adapt to living alongside his demonic siblings. His new reality brings far more than domestic adjustments, as dangerous rival demons soon emerge, intent on targeting Mio and Maria. Determined to keep them safe, Basara steps up as their protector, navigating treacherous conflicts against formidable adversaries. Yet, surviving external threats is only half the challenge. Amidst the chaos of battle and hidden identities, he must also contend with the girls’ intense, devilish appetites, leading to a whirlwind of passionate encounters that constantly test his resolve and redefine his strange new life.