Lab rats and cats

Two boys are raised in a laboratory, subjected to experiments and isolated from the outside world. Though they grow close during their time there, one of them carries a secret: they've actually met before, long ago before the lab, before the experiments. Only Atsushi remembers half of that brief but meaningful encounter from their childhood. Desperate to reconnect with that lost bond, he gently tries to help the other remember on his own, hoping the memory will return naturally.

But things aren't so simple. Their memories are fractured by trauma, manipulation, and the lab's interference. Strict surveillance, constant testing, and emotional suppression make it almost impossible for the truth to come out. As the boy who remembers grows more determined, Atsushi efforts are met with resistance both from the other boy, who feels a strange, unexplained familiarity but can't place it, and from the environment that keeps them apart emotionally and physically.

Their shared past is the key to something greater, but the obstacles they face may bury it forever.

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This story is also on my AO3 account