One possible plotline could be Kushina's daily life taking care of baby Naruto. She might be shown singing lullabies to him, or just watching him sleep with a loving look. Another could be about Naruto showing early signs of his ninja abilities as a baby, like accidentally using chakra in a cute way while Kushina tries to figure out what just happened.
A plotline might involve Naruto traveling back in time and meeting Kushina when she was young. They could start as friends and gradually fall in love. Or perhaps there's a prophecy that links them together, and they have to fulfill it, which leads to their mating. There could also be a situation where a powerful enemy forces them to work closely together, and that closeness turns into a deeper relationship.
One possible plotline could be that Kushina is somehow mind - controlled or influenced by an evil force to harm Naruto. Maybe she's under a powerful genjutsu that makes her see Naruto as a threat to the village instead of her son.
A plotline might involve Kushina being a 'psycho' due to some past trauma. This could lead to her having a hidden agenda within the Hidden Leaf Village. She could be secretly plotting against some of the village leaders while pretending to be a normal citizen. And Naruto, being her son, gets caught in the middle of her schemes and has to figure out how to deal with her and protect the village at the same time. It could also show how Naruto's friends react to this new, darker side of Kushina.
A possible plotline is that Naruto gets adopted by a group outside the village. He grows up learning their ways and becomes a sort of outcast from Konoha. Then, he could return to the village with a different set of skills and a new perspective. Or, he might develop a vendetta against Konoha for allowing his abandonment and try to take revenge in some way.
One possible plotline could be Naruto's struggle with abandonment issues. Since Kushina left, Naruto might have a harder time finding his place in the village. He could become more withdrawn and have to fight even harder to prove himself. Another could be the search for Kushina. Naruto might embark on a journey to find out why she left and try to bring her back.
One possible development for Naruto is that he begins to show signs of leadership. Even as a baby, he might gather the other village kids around him and lead them in some small play - adventures. For Kushina, she could develop a more nurturing side. She might start to think more about the well - being of the whole village because she realizes that Naruto will grow up in this environment. So, she could be involved in activities that improve the living conditions in the village, all because of her love for Naruto.
One possible plotline could be that Naruto is influenced by some dark force and turns 'evil'. Kushina, having come back to life somehow, tries to understand what has happened to her son. She then embarks on a journey to find a way to reverse the effects, leading to a series of adventures where they interact in different ways, like Kushina trying to jog Naruto's memories of their family bond.
A possible plotline is that the tail plug was a cursed object that was placed on Kushina by an enemy long ago. Naruto discovers this and tries to break the curse. He goes on a journey to find a way to remove the tail plug and free his mother from its negative effects, all while facing various challenges and enemies along the way.
One possible plotline could be that Kushina's survival changes Naruto's upbringing completely. Instead of being an orphan, he grows up with a loving mother. This could lead to him being more confident and less of an outcast in the village at a young age. He might also learn about the Uzumaki clan's secrets earlier from his mother, which could make him a more formidable ninja even faster.
Another plotline could involve the Shinigami within Naruto having some sort of mission related to Kushina. The Shinigami might need Naruto to help Kushina fulfill an unfinished task. As Naruto and Kushina work together, they also get to bond on a deeper level, with Naruto learning more about his mother's past and her love for the village and his father.