Basara Toujou discovers his new sisters are actually a fledgling demon lord and a succubus. He must protect them from warring factions while mastering his own dormant powers.
Why it's similar: This is the closest match in terms of tone, blending heavy fan service with high-stakes demonic battles. Both series feature a protagonist who enters a master-servant contract with a powerful female demon.
Power comparison: It trades Sacred Gears for magical contracts and elemental swordplay, but the intensity of the supernatural duels feels very familiar.
Why watch after High School DxD: Watch this if you want the exact same balance of action and romance that DxD provides.