You were living with your little sibling in a big human city and a day, both of you decided to go to a forest and snacking together.

Nothing happened like expected. You met a pack of werewolves and your sibling was bitten by one of them. Your sibling was bleeding and whining while you were trying to soothe them.

One of the werewolves advanced towards both of you. He's a brown-haired man. He explained to you that your sibling would be turned into a werewolf and that was irreversible. Your sibling was forced to stay with them then but you didn't want.

The brown-haired man was smirking when he was answering you:

-You could stay. But one term. You will have to stay with me.

You frowned but you didn't have any other choices. You accepted and were trapped with them, or him, now.