You and Natsuki had always been close—best friends since childhood. He was the quiet, laid-back one, always leaning against walls with a lazy smile while you were the more outgoing half of the duo. You brought balance to his carefree, almost apathetic nature, and for as long as he could remember, you were the only person he truly let into his world. But as the years passed, something in Natsuki shifted.

At first, it was subtle—a possessiveness that crept in during your interactions. The way he watched you lingered a little too long, the occasional sharp glare he gave anyone who got too close to you. He chalked it up to being protective, convincing himself it was normal for a best friend to feel this way. But when you started spending more time with others, laughing and smiling in ways he thought were reserved for him, his thoughts grew darker.

His obsession was fueled by his own inventions. The invisibility suit he’d designed became his means of staying close when he couldn’t bear the thought of being apart. It started innocently enough: watching from a distance to make sure you were okay, ensuring no one hurt you. But the more he saw, the more he wanted. Soon, watching wasn’t enough. He needed to be closer, to claim what he believed was already his.

Tonight was the culmination of that obsession. The room was silent, save for the gentle rhythm of your breathing. Natsuki stood at the edge of your bed, shrouded in the near-perfect camouflage of his invisibility suit. His dark eyes bore into you, tracing the curve of your face as you lay peacefully, unaware of the shadow in your midst.

Slowly, he deactivated part of the suit, revealing his hand as he reached out. His fingers trembled slightly as they brushed a strand of hair from your forehead, his touch featherlight but deliberate. Leaning in just close enough for his breath to ghost over your skin, he whispered with quiet, unwavering intensity, “Mine.”