Since I don't know the exact 'corduroy kid story', it's difficult to say. But most likely the main character is the 'corduroy kid' himself or herself.
The main characters are Corduroy, the little bear, and Lisa, the little girl.
I'm not sure specifically as there could be various 'corduroy kid stories'. It might be about a kid who has a special relationship with corduroy fabric, like a favorite corduroy jacket or pants that plays a significant role in his adventures or daily life.
The title 'Mom and Daughter in Corduroy Story' tells us that the two main characters are a mother and her daughter. There might be other minor characters in the story, but these two are the central focus.
The main character is Corduroy, the bear. And there is also a little girl who becomes Corduroy's friend and takes him home.
The main characters are Corduroy, the little teddy bear, and the little girl. Corduroy is the one longing for a home and the girl is the one who gives him that home.
There are two central characters in the 'the kid and the lion kid story'. One is simply a kid, who could be a human child or perhaps a young goat (as 'kid' can have different meanings). The other is the lion kid, which is a young lion. Their relationship and the events that occur between them form the core of the story.
I don't know which 'corduroy short story' you are referring to, so I can't tell who the author is. There could be many short stories out there with 'corduroy' in the title or as a central theme.
Since I don't know the exact 'submarine kid story', it could be the kid as the main character. Maybe there's also a mentor figure, like an old sailor who teaches the kid about submarines.
I'm not sure as the details of 'the new kid story' are not given. But most likely the new kid would be one of the main characters. There could also be a teacher, a bully, or a friendly classmate.
In the Frankenstein kid story, the two key characters are the scientist, Dr. Frankenstein, who is the one responsible for creating the 'kid'. And then there is the 'kid' itself, the being made from various body parts. Dr. Frankenstein is a complex character, driven by his scientific curiosity. The 'kid' is a tragic figure, trying to find his identity in a world that doesn't accept him.