In the dimly lit confines of their shared room, Rimu and Himeno find themselves in a precarious situation. Their parents, oblivious to the tension, have left them alone, igniting a forbidden curiosity between the siblings. Rimu, the elder, notices Himeno's innocent glances at his growing bulge, while Himeno can't help but steal glimpses of Rimu's toned physique. Their whispered arguments mask a growing desire, culminating in a heated moment where Rimu's hand brushes against Himeno's thigh, sending electric shocks through both their bodies.