It could also be one of Star Fox's close friends. Maybe they go through some situation together that causes the weight gain. For instance, they get trapped on a planet with limited food options, and the only available food is really fattening. So this friend of Star Fox is the main character who has to deal with the weight gain and its consequences.
Obviously, Star Fox himself could be the main character. Since it's a 'Star Fox weight gain story', he would be the one experiencing the weight gain.
It could be Chewbacca. Imagine Chewie getting stuck on a planet with limited food options that are all high - calorie. He might start to gain weight as he tries to survive on whatever he can find. And his weight gain could affect his ability to move around quickly, which is usually one of his advantages.
Obviously, Star Fox and Wolf would be the main characters. Star Fox is known for his agility and heroics, and Wolf is his fierce rival. In this story, their relationship could be further explored as Wolf deals with his weight gain.
Well, perhaps in the story, Star Fox discovers some super delicious but very high - calorie food on a new planet. He can't resist it and starts eating a lot, which leads to his weight gain.
Well, it could be about how Wolf, perhaps due to some strange power or a change in his lifestyle, starts to gain weight. Maybe he's been eating too much of the alien food during his space travels. And Star Fox might initially make fun of him but then realizes it's a serious issue and tries to help him get back in shape.
A young girl from a poorer district might be the main character. If there was some sort of relief effort where the Capitol sent a large amount of food to her district, she could be one of the first to gain weight. This would make her stand out in her district, and she might face both envy from those who are still starving and criticism from those who believe in the traditional, more slender body type of her district.
Perhaps an older, veteran hunter. After years of successful hunts, they start to relax a bit. They become less strict with their diet and start to gain weight. This weight gain makes them re - evaluate their hunting skills and they have to find new ways to be effective in the field again.
The main character is the birthday boy, of course.
Rias could also be the main character in such a story. Imagine if she goes through some sort of magical accident that makes her gain weight. As a high - status devil, this would be a huge blow to her self - image. She might become a slob as she struggles to come to terms with her new body, and it could be interesting to see how she tries to regain her confidence and status within the school and the devil society.
One example is Adele. She has been open about her weight gain and journey. Her body has changed over the years, and she has faced public scrutiny regarding her appearance. However, she has also been an advocate for self - acceptance and has focused on her music and her personal growth.
Perhaps it's a story of a young Jedi who, after being injured and unable to train as rigorously, starts to gain weight. This change in his physical state could also lead to a change in his self - esteem and his relationship with the Force. He might have to learn to accept his new body while still finding his place in the Jedi order.