The past years of his life, Haruto has not been very productive, to the point of living locked in, loitering non-stop.
But one day something happens, and faced with a clueless goddess, he receives the opportunity to reincarnate in a new world.
He wakes up in the body of a newborn baby, and though he has doubts as to how he died, he meets with his new family. He notes that they are from a noble family, and that it seems they will measure his magic level.
But even though the goddess offered him great powers, according to the magical artifact they use on him, he is as weak as a baby… from his old world.
As Reinhardt Orteus, he was supposed to become the prince of the kingdom of Orteus, but it is unfortunate for his parents that his power is so limited, and they decide that the fairest thing to do is to say that the child did not survive the birth and get rid of him immediately.
The boy is abandoned in an area where monsters will come out to devour him, and although he is totally alone, Haruto does not despair and begins to experience the use of magic, although he cannot even stand up.
As he practices, a huge monster appears and tries to eat him, but Haruto is able to fight back, and even subdue the creature named Flay.
Flay feels defeated, and she knows that she will lose her life, but Haruto tells her that he has no intention of killing her. Flay is moved and tells Haruto that her life belongs to him, that from then on he will serve him. To do so, she transforms and takes a nearly human form and offers her body to him to feed.
Flay can sense Haruto’s power, and mistakes him for the Demon Lord. In those moments, a gentleman appears, who tells Flay that he has come to save the baby from death, that he lost a son a long time ago, and wants to adopt him.
The boy communicates with Flay and tells her that he is fine with the idea, that she cannot feed him, but this man and his family can. Flay agrees, but tells the man that she will be with him for the rest of his life.
Like this, Haruto finds a home, and Flay a job. Years later, Haruto is back to being the same old slacker, but his body is different from others, and when called upon, he responds with agility and power that somewhat scares his adoptive father.
Now, he has a younger sister, Charlotte, but for some reason he can’t communicate with her as he would like, but Haruto is happy for her when he sees how she plays and has fun with Flay.
The future will be bright for Haruto, although the lazy one doesn’t want it that way.