Senku had been working on the stone world telephone for days without rest. You hadn’t thought much of it at first—he was always obsessive with his projects—but tonight, you heard it. A faint, pained groan slipping through the silence.

Concern tugged at you as you dragged yourself from your bed. Still half-asleep, you padded quietly to his lab, rubbing at your eyes. The room was dimly lit, shadows clinging to shelves stacked with tools and half-finished inventions.

The moment you stepped inside, Senku’s eyes snapped to you. He froze, caught like a guilty child. Then, in an instant, he turned away, shoulders stiff, as if trying to hide something.

But you had already seen it. A fleeting glimpse of color across his cheeks, the heat of exhaustion in his face. His breaths came too fast, too shallow. Fever? A cold? Or… maybe you were just imagining things in your sleepy haze?

“A-ah… Rina,” he muttered, his attempt at composure cracking as he cleared his throat. It only made his voice raspier. “What are you doing here so late?”

There was something off in his tone. Gone was the sharp confidence, the cocky bite he usually carried like armor. Instead, his words wavered—hoarse, unsteady, vulnerable.

“I’m just… working on the telephone.”