Disclaimer: Fruits Basket is the property of Natsuki Takaya. The following is a work of fanfiction based on that property. This work is unofficial.
His meals came twice a day. Every two weeks people would come to spray for insects and clean the window.
It was the window that bothered him the most. There was only one, deep-set in a thick wall. It was tall but narrow—perhaps one foot across—with bars embedded within it in a grid pattern. There was no glass. The night air in June was humid, stagnant; if anything it made the smell worse.
Mercifully, they had installed screens on both sides of the bars. There was a difference between imprisonment and outright torture, and it was a line the family didn't want to cross. He was an outcast, he was hated, but he was still "special," and they had reason to keep him alive for as long as possible.
The layers of mosquito netting over the small building's entrance had come later: it kept him safe; it kept them out.
It didn't keep them away.
He didn't look at the window anymore. He didn't look at the shadows cast on the opposite wall when the moon emerged from the clouds. His sensitive ears could still hear them.
It began with anger, despair, and his terrible loneliness. Without the beads his emotions had betrayed him, as they always did: he was unable to maintain human form.
He'd come tantalizingly close a few times: for a few moments he would have human hands, hair, body. He would remember her smile, how it had calmed him, reassured him, given him the hope and acceptance he so desperately craved.
Then his thoughts would return to the fact that she was not here, despite her wish to "stay together." And then they would invariably return to his mother, who hadn't wished to "stay together," who had abandoned him in favor of a speeding train.
And then his humanity would abandon him, as it always did. The sudden embrace in the woods three years ago had been out of desperation as much as relief: his wrist was bare, and he didn't want to see the fear return to her eyes when he cried.
All of those incidents were in the past; a human body was only a dream. He was a monster, and had been for a very long time. Now his daily thoughts were focused almost entirely on trying to ignore the ceaseless buzzing, and the delicate rustling, and the writhing shadow on the wall.
His anger had given way to fear gradually. For much of his life he had been hiding his fears, and his guilt, and his anxieties behind anger, but things had never been like this. He was all alone and was genuinely, viscerally frightened of the things covering the window screen, and the fear would not leave him. What would happen if they got inside? He was trapped and surrounded: a monster in a room—all claws, teeth, eyes, and the overpowering stench of rotting flesh, like something dead.
It had never really occurred to him before his confinement that there were things—tiny things—that sought out dead things and desecrated them. Now they haunted his thoughts and his dreams.
He smelled like a battlefield.
He was afraid to go outside.
The door was unlocked—had been for nearly a year now—but he stayed inside (as his mother had taught him) in the dark. For all of its size, the window didn't let much light in; most of the screen was obscured.
Cats didn't visit him anymore. Other things visited... and lingered.
Nameless people (caretakers; zookeepers) visited regularly but they never stayed long.
His meals came twice a day.
Every two weeks people would come to spray his room with poison, and scrape his nightmares off the window.