遡ること半世紀。異世界の存在が確認される。そこは、人類の新天地になるはずだった。

しかし、莫大なコスト面と、先遣隊の全滅、世論の反対により不可侵条約が結ばれる。

人類の目は宇宙に向けられた。

しかし、現在。異世界のダンジョンに潜る為、ある企業が部隊を編成する。

五人のプロフェッショナルと三機の人工知能。それに予備の人員一名。

現代火器と技術により、冒険は簡単に行く予定だった。

だが異世界にたどり着けたのは、ポンコツの人工知能とノンプロフェッショナルな一名。

試行錯誤を繰り返して、彼らは生きる、食べる、戦う。そして、ダンジョンに潜る。

It was in 1946 that Earth learned of the existence of other worlds. As expected, many countries immediately tried to send people into the other world, hoping to obtain vital resources or mystical treasures. None of them came back.

And to be fair, Souya never expected to be one of those explorers. But here he was, accepting an offer by a shady company to get enough money to save his little sister. Launched into another world, he soon finds that his journey will be a hard one – not only have his teammates gone missing, but a majority of his food and weapons supply was destroyed in the transfer.

The only way left to go is forward. With only an AI companion to guide him, Souya ventures forth, hoping to find something worthwhile that will justify sending a rescue party to save him – if such a party comes at all.