Imouto Haramasenai to Derarenai Shima

In response to the nation's severe declining birthrate, the government has implemented an extreme countermeasure: mandatory reproduction. Caught in this unprecedented policy, a brother and sister are selected and sent to a remote island with a strict condition—they cannot leave until they successfully conceive a child. Isolated from the rest of society and completely devoid of any other form of entertainment or distraction, the siblings find themselves trapped in a situation that challenges everything they know about their relationship. For years, the two had shared a comfortable, platonic bond, interacting more like close friends than anything else. Initially, they treat the absurd mandate as a joke, brushing off the pressure with lighthearted banter typical of their dynamic. However, as days turn into weeks on the secluded island, boredom sets in and their options dwindle. With nothing else to occupy their time, they inevitably begin to view one another in a new light. The casual boundaries that once defined them start to erode, and what began as playful teasing gradually shifts into a growing, undeniable awareness. Slowly but surely, the siblings find themselves losing the restraint that once kept their relationship firmly in check.