Gal Big Sister Z

A revenge fantasy visual novel where the protagonist, Daiki, discovers a hypnosis device that lets him control his two domineering older sisters. Raised under their tyranny—forced to do all housework and emotionally abused—Daiki obtains the device and begins systematically reversing their power dynamic. The game explores how the hypnosis gradually reveals hidden aspects of each sister: buried vulnerabilities, protective instincts, and suppressed desires. What begins as crude revenge evolves into a more complex relationship as humiliation gives way to genuine connection and role reversal. Gameplay centers on customizing hypnosis effects through a tablet interface, combining different commands to create varied scenarios with the sisters. The visual novel features full voice acting and animated intimate scenes rendered in high-quality motion graphics. As Daiki experiments with the device, he uncovers the true personalities his sisters kept hidden, and the story shifts from simple domination fantasy toward exploring what might lie beneath their cruelty.