Description

Niihara Daiki has spent his whole life as his sisters’ personal errand boy. The moment he’s home, every chore lands on him, and any attempt to protest earns him a beating and a one-sided framing as the bad guy. That’s been his daily routine for as long as he can remember, ruled over by the domineering sisters who look down on him. Fed up with the endless cycle, Daiki hears about a hypnosis device from an upperclassman at his university. He tries it half in disbelief, but the effect is immediate: his sisters become obedient to his every command. Those sisters who tormented him now do whatever he says, and Daiki starts using the device at home to vent all his pent-up resentment. But as he leans into his new power and settles old scores, the situation takes a turn he didn’t anticipate. Gal Big Sister Z follows Daiki’s revenge-driven household reversal, where the tables finally turn on the sisters who made his life miserable.