High School DxD: That Time I Got Reincarnated as a Nephilim

Ordinary office man Kazuma Ragnvaldr died due to overwork. For that reason, when he finds himself reborn as an nephilim and son of the seraph Gabriel, he decides to live an easy-going life. Unknowningly, at 5 years old, he unlocked his Sacred Gear "Infinity Ciphering" and his own system allows him to travel dimensions.