Obviously, the good soldier is a main character. There may also be his commanding officer who gives him orders and influences his actions.
Perhaps there are veteran soldiers who pass on their wisdom and experiences to the new recruits in the 'Soldier Story'. These veterans with their years of service and numerous stories could be main characters.
There is Captain Edward Ashburnham, who is the 'good soldier' of the title. He appears to be a proper and noble military man on the surface.
Well, if it's a typical 'little soldier story', there would be the titular little soldier as a central character. He could have a mentor figure among his superiors, someone who guides him. And his fellow soldiers would also be important characters. They might be from different backgrounds and personalities, and together they form a unit. The enemies in the story would also be key characters as they create the conflict that the little soldier and his comrades have to deal with.
In 'the first soldier ff7 story', apart from the first soldier, there could be other key characters. There might be a mentor figure who teaches the first soldier the ropes. There could be fellow soldiers with different personalities and abilities, some might be more experienced and help the first soldier, while others could be jealous or competitive. Additionally, there may be characters from different factions or races in the FF7 universe that interact with the first soldier and influence his story in various ways.
Since it's called 'ff7 first soldier story', we can assume there will be at least one main soldier character. Maybe there will be a mentor figure or a rival among the main characters as well. However, without more information, it's difficult to be more specific.
I'm not entirely sure, but probably the First Soldier himself is a main character. There might also be other characters related to him, like his comrades or his superiors.
The main character is the little tin soldier himself. There might also be other characters like the paper ballerina.
The most important character in 'the tin soldier short story' is surely the tin soldier himself. He is the one whose story we follow. Then there is the boy. The boy is the one who has the tin soldiers and sets them up in different situations. He causes a lot of the action in the story because of his playing with the tin soldiers. Another character is the paper ballerina. She is sort of an object of the tin soldier's affection. He is drawn to her, and she plays a role in his journey as well.
Since I don't know the specific 'little big soldier story', it's difficult to say. But likely there would be the 'little big soldier' himself, who could be a young, inexperienced or small - in - some - way soldier. There might also be his comrades, like other soldiers in his unit. And there could be antagonists such as enemy soldiers or perhaps a cruel commander on his own side.
I'm not entirely sure specifically for 'ff7 the first soldier story', but it might include characters related to the soldier, like their comrades in arms, or perhaps some of the main antagonists in the FF7 universe such as Sephiroth.