Uraniwa No Kakushi Dungeon De "Kigyo" Shi, Nenshu 120 Oku En Wo Tassei Suru Tame No Senryaku (EARTH STAR NOVEL ESN358) [Light Novel]

[Machine Translation] The world's energy situation has drastically changed with the discovery of magic crystals mined from dungeons - ores that are clean and highly efficient in energy conversion. The dungeons, which were initially controlled by the government, are now open to the private sector, and many (minorities) dive into the dungeons in hopes of getting rich quick. Hiroshi Tsukino, who works for a subsidiary of an advertising agency, buys a house in Isehara City in accordance with his life plan (if he cannot get married by 40, he will buy a second-hand house in the suburbs and live in peace and quiet). However, in the backyard of the house he bought with the intention of spending a leisurely life, there is an opening to a dungeon.... Tsukino's encounter with the backyard dungeon puts him at a crossroads in his life, and at the same time, he is faced with a major incident at his workplace.

ダンジョンから採掘された魔結晶―クリーンかつエネルギー変換効率の高い鉱石が発見されたことにより、世界のエネルギー事情は激変した。当初は政府が管理していたダンジョンが民間に開放されたことで、一攫千金を目指してダンジョンに潜る「マイナー」が数多く生まれる。広告代理店の子会社に務める月野宏は「40までに結婚できなければ、中古でいいから郊外に家を買い、のどかに住む」という人生設計に従い、伊勢原市の一軒家を購入した。しかし、のんびりと過ごすつもりで買った家の裏庭には、ぽっかりとダンジョンの入り口が口を開けており...。裏庭ダンジョンとの邂逅により、人生の岐路に立たされた月野だが、時を同じくして、自らの職場でも大きな事件に直面することに。