well, let's go. the story is very good, the development is good, the interaction between the characters is good, the personality is good, everything is great in this story. however there are still some things that I personally did not like.
FIRST: it was the speed of history. I read until chapter 8, the epilogue of vol.1, and I found the development very slow, the chapters are long, I don't know exactly how much, but about 5000 words or more, and with so many words these 8 chapters could cover almost 50 chapters from other stories, and despite that Mc is only 5 or 6 years old, so far the story is more like a slice of life than anything else.
SECOND: it was that the author decided to make one of the taboos of stories of reincarnation that was Mc talking about his reincarnation with his mother. from that point on I felt that the interaction between Mc and his mother was completely forced, not because the author wrote this interaction in a bad way, but because, with you aware that your mother knows that despite his infantile body he he is already an *****, the way they act simply "does not make sense", so the situation does not seem to fit, so for me the interaction between the MC and his mother after this point were situations that I did not like to read, I preferred Mc's interaction with any other character than reading him and his mother talking.
THIRD: it's a very personal thing so it doesn't serve as a criticism, which is the fact that the MC's personality seems to be that of a "hero" if you know what I mean. personally I prefer more selfish characters, who act for themselves or for those he likes, but so far it doesn’t seem to be the case for this character, at least I understand his personality (SPOLER: and I’m not just talking about how he acted to save Rias and Sona).
Overall the story is great and very well done, unlike other authors who write without thinking too much to kill time, the author seems to be taking it seriously, but personally I think the author should increase the pace of the story (I'm not talking about chapter updates, but the speed at which the story goes).