In the 'diaper days story', the main characters may include the infant who is in the diaper - wearing phase. This little one could be the focus, with their actions and reactions being central to the story. Additionally, if it's a more complex story, it could feature pediatricians or nurses who are involved in the baby's health during these diaper days. They could provide advice on diaper use, dealing with any potential health issues related to diaper - wearing, and so on.
Since I don't know the details of 'the diaper school story', I can't say for sure who the main characters are. It could be the children in the school, or the teachers who take care of them.
Since I don't know the exact 'diaper boy story', it could be the boy himself as the main character. There might also be his parents or caregivers if the story focuses on his family situation.
I'm not familiar with the '91 days story' specifically, so I can't name the main characters. However, they might be individuals with different personalities and goals. There could be a protagonist who drives the story forward, and perhaps some supporting characters like friends, family, or colleagues who interact with the main character during the 91 days.
There are several main characters in the '19 days story'. For example, Jian Yi and Zhan Zheng Xi are among the important ones.
Since I don't know the exact story, it's hard to say for sure. But most likely the flower girl would be one of the main characters. There could also be her parents or guardians who are responsible for her and the diaper situation. And perhaps there are other people at the event, like the bride or groom if it's a wedding - related story, who interact with the flower girl and are affected by the diaper situation in some way.
Since I don't know the details of the story, I can't say for sure. But it might be the diaper - wearing boy himself as a main character. There could also be a camp counselor or a fellow camper who plays an important role.
If it's related to the regular Family Guy plotlines involving diapers, Stewie would likely be a main character as he is a baby. His diaper - related situations are often part of the humor.
As I don't know the details of this story, it's impossible to say who the main characters are.
There could be a popular girl who discovers the diaper situation and she becomes a main character in the story as she either helps or teases the person involved. And perhaps a strict teacher who also plays an important role in how the situation unfolds regarding the diapers in the high school setting.
Since I don't know the exact story, the main characters could be the diaper boy himself, obviously. And probably the daycare workers who take care of him.