There was once a man called Gregory, though he preferred to be called Greg. He was a rather quiet person with an active imagination but a high tendency to shy away from confrontation. As a result, he struggled with interacting with others and became rather withdrawn.
Yet every night when the clock struck ten, Gregory would change, thanks to a mysterious girl who appeared at his door every night without fear. Whenever she arrived Gregory would smile and felt his troubles fade away as he took her hand and went outside.
The girl never gave a name, but Gregory never asked; it was as if he had known her his whole life and he trusted her completely. The pair would go on long walks down the streets and laugh at the world around them.
Occasionally, people would stop and stare. The normally timid Gregory would feel deep anger every time - how dare they stare like that? Damn freaks. So he'd yell at them and frighten them off, sometimes yelling had the opposite effect and someone would try to pick a fight.
The girl would get scared and Gregory would lose control, almost as if he was drunk, attacking those who dared to ruin his night out. Sometimes Gregory even ended up in a jail cell overnight, yet even in the cell his mysterious friend would stay with him until the sun came up. Gregory never questioned how she did it (or why); it was as if the world could not see her. Yet Gregory knew she was real.
When the sun rose, Gregory would finally succumb to growing exhausted and close his eyes. When he awoke, the girl would be gone and he began to retreat back into his quiet shell; avoiding conflict as much as he could. Avoiding people as much as possible until the clock once again struck ten at night and the cycle continued over again.
What Gregory was unaware of, was that he was actually a fraternal twin; his sister having died shortly after birth. His parents never told him about the tragic event and he was raised as an only child.
They hadn't even managed to name the girl before she died.