Humanity’S Existence Depends On Love Gambling With Another World’S Princess summary: Interactions between this world and the one ruled by the demon lord have grown increasingly common. Unaccustomed to teaching the denizens of another world, Itou Kazuki becomes perplexed when the demon lord's daughter, an avid fan of shoujo manga, transfers into his class. "If you make my daughter cry, I'll destroy your world."