An SI In High School DxD

A normal man was walking home one night and suddenly found himself in another world. No explanation. No meeting a ROB. Nothing. He doesn't have a system or any cheat powers, just his own mind and years of experience. What happens when a regular guy gets sent to the land of gravity defying breasts and overpowered world enders? Let's find out! Please note: HighschoolDxD is (C) and (TM) by it's respective owners. I'm just playing with the material. — Description from novelcodex.org