It might be a protagonist who is new to the area and experiences the first snow in a completely different way compared to what they are used to. There could also be a local character who guides the new person through the joys and challenges that the first snow of winter brings.
Since I don't know the exact 'the first snow of winter story', it could be a young child who is excited about the first snow. Maybe a family with parents and kids.
Not having read 'the first day of winter story', we can only speculate. It could be a young couple who are having their first winter together and are learning to enjoy the cold days and long nights. Maybe there's a local guide in a small town who shows the newcomers around during the first day of winter, and that guide could be one of the main characters. Or it could be a family with a small child who is seeing snow for the first time on the first day of winter, and the family members are all important characters in the story.
Snow White is central to the story. She is the target of the queen's envy. The Huntsman is an important character as well. He has skills in hunting and survival, which he uses to help Snow White. The evil queen is another main character. She has powerful magic and is willing to do anything to stay in power and get rid of Snow White. In the 'Winter War' part, there may be other characters like Snow White's allies, perhaps some brave soldiers or magical creatures who join her fight against the queen's forces.
Typically, there is the Snow Queen herself as a main character. And there is usually a young hero or heroine who goes on a journey in her icy world.
I'm not sure as the 'Winter Story' isn't defined in detail. But it could be a family trying to stay warm during a harsh winter, so the main characters would be the parents, children, and maybe an old grandparent.
I'm not sure specifically about the 'the first snow of winter story' as there could be many stories with this title. It might be about the beauty and magic that the first snow in winter brings, perhaps with characters experiencing the cold, the transformation of the landscape, and the special moments that come with the first snowfall.
Perhaps there are some unique characters like a little snowman named Frosty who becomes friends with the kids. And also a kind old man who lives in a cabin in the woods and gives the kids warm cocoa during their winter adventures.
I don't know exactly as I haven't read it. But perhaps there could be a young man and a young woman.
In the 'king winter story', King Winter is probably the main character. However, depending on the nature of the story, there could be other important characters. For example, if it's a story about a journey, there might be a group of companions who accompany King Winter. These could be a wise old man who has knowledge of the winter magic, a young boy who is eager to learn from the king, and a talking animal, like a wolf or a raven, which could be his guide or messenger.
Since I don't know the specific 'kid winter story', it could be a young boy or girl as the main character. Maybe there are also some friendly animals like a dog or a rabbit.
Perhaps the main characters are a group of friends. They could be planning a big Christmas event in their small winter town. One of them might be a bit of a Scrooge at first, not really into the Christmas spirit, but through the events in the story, like helping the local orphanage or decorating the town square, they come to embrace the joy of Christmas.