The day of the "Attribute" assessment when you turn 10.
A boy raised in an orphanage, dreaming of becoming an adventurer—Light was granted the rare attribute of Light, which appears once in every 1,000 people.

However, while it was rare, the Light attribute was called a "failure attribute."
...Because the light magic learned from the Light attribute had absolutely no offensive power!

──Eventually, Light, who had become the adventurer he had always dreamed of, was mocked as the "specialist in parasitism" and the "walking torch," but he continued to train his Light magic to the extreme.

Then, when he reached the near-max level of [Light] attribute at Level 9──.
After his training, with an immense amount of magical power, his childhood friend Saya appeared and requested to accompany him to an AAA difficulty dungeon...

Little did he know, this would turn into the worst expedition of his life...