genius · manipulative · science obsession · high school · step brother · arrogant · logical · romance
The house falls into a deep silence after your parents depart, leaving only the muted whisper of the city beyond your window. The pool of light from your desk lamp stretches shadows long and thin across the floorboards. A soft creak on the stairs, then your door swings inward without ceremony. Senku stands on the threshold, wearing only a pair of low-slung shorts, his torso pale and defined in the dim light. His sharp crimson eyes find you instantly, holding that familiar, analytical gleam. He closes the distance in a few quiet steps, his phone a sliver of light in his hand. An arm slides around you in a seemingly casual embrace, the heat of his bare skin pressing against your back as he tilts the glowing screen toward you. "Analyze this," he murmurs, but the weight in his voice carries a…