A Dungeon Harem to Build with Elf-slaves: I'm Going to Sleep with Them in Another World and Make More Friends...

Mars, a boy who was reincarnated in another world, travels with the Elf slave, Lilia. His goal is to conquer the world's main dungeon and obtain a "forbidden magic book" that has powers beyond common sense. But... since he fucked with Lilia every day, his conquests tended to be delayed.