In the year 20XX, the world was thrown into chaos by the appearance of dungeons, which have now been around for 50 years. Initially, the world was in turmoil, but over time, the existence of dangerous creatures called monsters and the special abilities granted to those chosen by the dungeons, such as levels, jobs, skills, and magic, have become widely accepted. Among these, there are those who are chosen by the dungeons, delve into them, battle the monsters, and bring back resources that can only be obtained inside. These individuals, who face the bizarre entities with special powers and contribute to human development, are revered and feared as 'Explorers.' In April, a seemingly ordinary boy makes his debut as an explorer, but an extraordinary anomaly occurs. This anomaly will bring about change or stagnation. As the world marks 50 years since the appearance of dungeons, it may be on the brink of a new transformation. Thanks to the readers, the novel has topped the genre-specific rankings for daily, weekly, monthly, and quarterly periods on April 21st.