There may be some James Marsden gay fanfic out there. However, it can be difficult to find good ones. You might want to look for fanfic communities dedicated to his works or the shows/movies he's been in. These communities sometimes share and recommend fanfics, but of course, not all of them will be of the gay variety.
Archive of Our Own (AO3) is a great place to start. It has a large collection of fanfics on various topics and actors, including James Marsden. Just use the search function and type in relevant keywords like 'James Marsden' and 'gay' to narrow down the results.
Sorry, I haven't read it yet so I can't summarize it directly. But generally, you can start by looking at the main characters in the story. Maybe there are some rabbits that play important roles. Then consider the plot development, like what challenges or adventures they go through.
We don't have enough details to know exactly who James is. He could be an ordinary person with an extraordinary secret, or he might be someone well - known in a particular community or field.
In 'the James Mink story', James Mink might be a person with a particular set of goals or challenges. Maybe he's on a quest, or facing some sort of conflict. Without reading the story, it's hard to say more. But often in stories, characters like James Mink are used to drive the plot forward and teach readers some kind of lesson, whether it's about love, perseverance, or something else.
In 'my 600 lb life james story', James is the focal point. He is presumably a person whose life has been greatly affected by his 600 - lb weight. This story may chronicle his daily life, his relationships, and his attempts to make changes. He could be someone who has faced discrimination because of his weight, or he might have health issues directly related to it. His story might be one of perseverance in the face of these difficulties as he tries to better his situation.