"I cannot be the heir because... because..."
At first, Zoemi rolled his eyes and was going to shoot down Reo's question, but once he realized that ā Because I am a reincarnated person from another world ā doesn't actually speak against him, and maybe even gives it a little bit more validity...
He WAS born again, he didn't just pop into existence out of a thin air.
He did have a mother, although memories of a three-year-old child couldn't be said to be vivid.
Back then, Zoemi wasn't even properly aware that he was a reincarnated person, he was just a child who had strange dreams about living a different life and nothing else.
He lived with his mother in the slums, thinking how much better the life of the boy named Kuro Aku was.
If only the black-haired boy could remember the name of his mother, that would make everything so much easier - but the problem was that he always called her just mom, mommy, like any child his age would.