Board Thread:Naruto Discussions/@comment-26135923-20150707130017/@comment-5936871-20150709034149

@Chaos Well, even if it's possibly true that they have their souls. They still have their chakra, so that can be passed down. Kishimoto could have also made reincarnation work the way he wants it too in Naruto, it doesn't have to follow eastern mythology exactly. Also, Naruto is Asura's descendant. He's an Uzumaki, who come from the Senju, who come from Asura. Asura and Indra's chakra only incarnates itself into their descendants (Stated by Black Zetsu), so Naruto is his descendant.

The Uzumaki have the same red hair as Hagoromo anyway, same abilities that Asura had, and the fact that Asura incarnated into Asura means they come from him like the Senju do. Madara even stated he specifically gave Nagato his Rinnegan because of his Senju lineage, due to him being an Uzumaki. The Uzumaki are just red-haired Senju.

We also don't know if the beasts have souls, they're just giant monsters made out of pure chakra and given a body. When they die, they're reborn into the world eventually. They don't move on to the Pure Land, thus, they lack souls.

As for your edit, like I said, if Himawari did it I would find it cool. But I just don't think it fits Boruto.