While giving birth to her twin sons Hagoromo and Hamura, she dispersed chakra to them, making the pair the first people born with chakra. ... Eventually, Kaguya found herself ruled by her own desire to possess all chakra, which eventually turned her against her sons.

Why was Kaguya sealed by her sons?

Despite their different views, yet similar desire for world peace, its been implied that Kaguya's fraternal twin sons, Hagoromo and Hamura, might have gone against her at some point and that, put together with them leaving her after growing up and ultimately sealing her in the moon(though they were unaware of her at ...

Why did Kaguya become evil?

Hagoromo's ghost notes that she was well-intentioned but became twisted, most likely due to eating the Chakra Fruit. The anime develops her character, confirming that she was a kind soul who got corrupted.