Hachinan Tte, Sore Wa Nai Deshou! (readlitenovel-com)

Ichinomiya Shingo, a young 25 years old, single, worker of firm company while thinking of tomorrow’ busy working day goes to sleep. However the moment he woke up, it’s a room unknown to him. He then learn that he is inside a 6 years-old boy and is taking over his mind. He then learn a lot from the memories of the said…