Saitei Rank no Boukensha, Yuusha Shoujo wo Sodateru: Ore tte Kazuawase no Ossan ja Nakatta ka?

Overview

In an experiment to create artificial black holes or white holes for energy generation, things went awry. Instead, it opened a portal to another world, but not a friendly one. It connected to the dwelling places of creatures known as monsters. Amidst this chaos, individuals with supernatural abilities, similar to the monsters, emerged. They were known as “Awakened Ones.” Once awakened, they were obligated to serve for five years. Koosuke Igami, a 35-year-old middle-aged adventurer of modest Class 3 ranking, had been adventuring for nearly five years. He joined a team of beginner high-class adventurers, but he only had three months left until his five years were up, and he could retire from being an adventurer.

Source: AniList