In the 'Kuga Game of Chase Vore Story', Kuga is probably a very important character. Given the name, Kuga is likely to be the focus of the story. He or she (we don't know the gender from the name alone) might be a brave adventurer in the game, or perhaps a target in the chase. The story could revolve around Kuga's actions, decisions, and interactions during this chase scenario and whatever the 'vore' aspect implies in relation to Kuga.
Yuma and Tori could be characters from a small - scale, indie story that has a dedicated but not widely - known fan base. The fanfiction allows fans to expand on their relationship, imagining their married life in ways that the original story might not have delved into deeply, perhaps adding more depth to their characters and their connection.
I'm not entirely sure as it's not a very common or well - known mainstream story. It could potentially be about a character named Kuga involved in a chase scenario within a game, and perhaps 'vore' might be some sort of unique in - game mechanic or concept that is central to the story.
3:10 to Yuma is purely fictional. It was created for entertainment purposes and doesn't draw from real-life events. The plot and characters were made up by the filmmakers.