祖父過世後孤身一人的相馬一也，某日突然被以勇者的身分召喚到異世界。他所到達的，是宛如中世纪歐洲一般的艾爾孚利登王國。不是勇者僅僅身為平凡人的相馬秉持著合理性的現實主義與現代知識，逐次建立新的政策，整頓即將傾倒的王國財政體制。與相馬一同進行改革的是艾爾孚利登王國的公主-莉希雅-、王國武鬥第一的黑暗精靈-愛夏-、擁有伶俐頭腦的白夜、大食怪邦喬、歌姬的茱娜、能和動物溝通的少女-巴-等具有才智並充滿個性的夥伴。利用現代知識重建窮途末路的王國、奇幻異世界內政！

Adolf Hitler (1889-1945) was a mediocre who rose to power because of the blindness and ignorance of the Germans, who believed he was nothing more than an eccentric dreamer. But when the crisis of 1929 devastated the economy, the population, fearful of chaos and communism, voted for him. And no one defended democracy. As the dictatorship extended its relentless shadow, the leader claimed peace, but was preparing the Apocalypse.

Stacey Dooley looks at three countries in the aftermath of the economic crisis.