from I Am the Hero, and the Demon King Is Also Me
Lavinia is a female demon that came in Tsugari's world to convince him to become the Demon Lord of her world, as he was chosen since he is the son of the former Demon Lord (which was his mother). She acts as the replacement Demon Lord.
I Am the Hero, and the Demon King Is Also Me
Combines the legend of a demon king with a hero who crosses over time and other things. Involves traveling between a Japanese living room and another world.
