Clarifications.
Kaguya Otsutsuki was sealed, she could not simply kill her children, due to her love for them, she had no choice but to allow herself to be sealed, however she knew that her children would not live forever like her, she created a Chakra lump called Zetsu with the only reason to free her, despite this, Kaguya did not expect something, she unconsciously implanted in Zetsu her desire to have a son, a son who would not betray her. Zetsu with this idea manipulated Indra to make him the perfect son with whom to fuse and revive his mother, however he failed and Indra died, then he tried with Indra's reincarnation, Madara Uchiha, but he was only interested in fighting. Zetsu, tired of trying with Indra, decided to go for the other brother. He waited patiently for Hashirama's death. On the day of the birth of the next reincarnation of Ashura, he took advantage of Obito's anger and left Naruto without his father. His mother surprisingly survived. Zetsu was not impressed because even Mito Uzumaki was still alive at that time and looked just as young as when she was in her 20s. While Kushina was in the hospital, one of her White Zetsu infiltrated and fused with the young baby. Uzumaki Naruto, the fusion was a success, he just hoped to see how the child grew and thus be able to rest from his mission, Either way, Zetsu continued to manipulate Madara, planting the seeds to free his mother.
Note: What would you think of this story? I came up with several possible forms for this story. I had thought about putting Naruto in Kaguya's time, but I thought it would be a little strange if Kaguya had another son before Hagoromo's and Hamura betrayal. I also thought about doing the opposite that Kaguya had Naruto inside the seal, however it would be too boring, it would be more like a One-shot since it wouldn't be a story that tells more than Naruto and Kaguya's life in the seal and the upbringing of Naruto, and it would end with the release of these two to control the world