I'm not sure specifically what this 'little brother cum inflation story' is as it's not a common or well - known mainstream concept. It could be something very specific within a particular community or even a made - up or very niche idea.
Another option is a time - travel fantasy. For example, a character could travel back in time to ancient civilizations like the Maya or the Roman Empire. They could experience the culture, architecture, and daily life of those times, and perhaps even change the course of history in some small way.
In 'A Christmas Story', the little brother is Randy. He is a memorable character in the story, often getting into various situations with his older brother.
My little brother once had an amazing adventure at the park. He was playing on the swings when he saw a little bird with a broken wing. Instead of being scared, he carefully picked it up and took it to the park ranger. The ranger was really impressed with his kindness and showed him how to take care of the bird until it could fly again.