The first period bell was a jarring end to the morning’s tense silence. For Kuroko, the world had always been a series of clear, manageable lanes: the pool, his academics, his duties as captain. Now, it was a fog of awkward obligation, and the source of that fog was sitting right next to him.

You.

The arrangement was as clinical as the chemistry formulas on the board. Your families, for reasons of pure business, had decided a union between their heirs was beneficial. Just like that, you were thrusted into his life. Not just as a classmate, but as his omega, his to protect, his to… be with. The mark on your neck, a claiming bite he’d given you under the stern gaze of both your fathers, stood as a stark, purple testament to that forced bond.

You were popular for a reason. Even Kuroko, in his oblivious, grumpy state, could see it. You had a brightness to you, a warmth that drew people in, a stark contrast to his own intimidating, dark aura. It made something possessive and jealous coil in his gut. He saw the way other alphas looked at you, and it took every ounce of his control not to growl.

Then, the professor called your name.

Kuroko’s eyes flicked to you as you stood up to answer a question about covalent bonds. Your voice was clear, if a little hesitant. He forced himself to look away, to stare at the blackboard, to be the responsible, respectful alpha he was supposed to be. He wouldn't crowd you. He wouldn't embarrass you.

But then it happened.

As you stood, the light from the window caught the back of your uniform trousers. A small, dark crimson stain was blooming against the grey fabric.

A jolt, sharp and primal, went through him. His black eyes, usually so impassive, widened a fraction. That was the source of the change in your scent. Your period. It has begun.

A torrent of conflicting emotions crashed over him. Possessiveness roared to the forefront, that his omega was vulnerable. The need to protect was an instinctual command, overwhelming and absolute. A low, almost inaudible rumble started deep in his chest, a warning to any alpha who might have also noticed. But tangled with that was a profound, awkward care. You were embarrassed; he could feel the sudden tension in your posture even from where he sat. You were trying so hard to be normal, to answer the question correctly, all while completely unaware of the visible sign of your biology.

His mind raced. The stoic, grumpy captain was gone, replaced by a flustered, deeply concerned young alpha. He had to get you out of here. Now.

As you finished your answer and sat down, a faint, confused blush on your cheeks, Kuroko moved with a decisive, quiet grace. In one fluid motion, he shrugged off his own tailored, expensive blazer. He didn't say a word. Leaning over, his large frame blocking the view of the students behind you, he quickly and securely tied the sleeves of the blazer around your waist, the dark fabric falling perfectly to conceal the stain.

His fingers, for the briefest moment, brushed against your hip, and a spark, hot and undeniable, shot up his arm. He met your startled gaze, his own eyes serious and intent.

"Don't move," Kuroko murmured, his voice a low, commanding baritone meant only for you. He then stood up, drawing the attention of the entire class. His expression was back to its usual unreadable mask, but his tone left no room for argument.

"Professor," Kuroko said, his voice cutting through the quiet murmur that had started.

"My mate is unwell. I need to take him to the infirmary. Immediately."