One idea could be that the oc retains some memories of their past life. So they use their knowledge to change things in the pjs world. For example, they might know of a coming danger and work to prevent it.
Perhaps there is a dark force that is awakened by the oc's reincarnation. This force might have been dormant for a long time, and the oc's new life energy or something about their reincarnation stirs it. It could be a force that wants to destroy the balance of the pjs world, and the oc is the only one who can stop it because of their unique perspective from their past life.
I'm not sure specifically which 'bunny pjs a christmas story' you are referring to. It could be a story about a bunny in pajamas during Christmas. Maybe it involves the bunny's adventures on Christmas Eve or Christmas day, like going to see the Christmas tree or getting presents.
Well, in 'A Christmas Story', the pjs could be a symbol of the coziness of Christmas at home. They are likely to be warm and comfortable, which is important during the cold Christmas season. They also might have some sort of pattern or design that is typical of the era the story is set in, perhaps something like plaid or stripes, which gives a nostalgic feel to the whole story.
It could be a new character created by the author, like a young kunoichi from a small, far - away village. She might have special powers related to nature, like the ability to communicate with animals. This would make for an interesting dynamic when babysitting Naruto, as he's always been curious about different ninja abilities.
The OC could be a mysterious ninja from a far - off land. Sasuke might think this ninja has some secret knowledge about the Uchiha clan that he wants, so he kidnaps them.
The OC could be an outcast in the ninja world. They don't belong to any major clan and are constantly on the move. Hidan might see this OC as an easy target. The OC might have some unique skills, like being able to communicate with animals, but these skills are not enough to protect them from Hidan when he decides to sacrifice them for his own dark purposes.
For character development, the OC could be an outcast in her own community. When she enters the world of Inuyasha and Koga, she finds a new sense of belonging. Koga's wolf pack could initially reject her, but through her determination and kindness, she wins them over. Inuyasha's friendship also helps her to see her own worth. As the story progresses, she becomes a strong and respected figure, not just among them but also in the wider world of demons and humans they inhabit.