After failing to find a job and becoming a shut-in after graduating from college, Sagara Kurohiko, seeking a place to die, finds himself enveloped in a dazzling light during a typhoon in the mountains and loses consciousness. When he wakes up, he's in an unknown land—a country with a unique culture centered around a sacred tree. He's been transported to another world, and he's also reverted to his teenage years. Kurohiko can somehow easily read an ancient forbidden spell book that no one else could decipher. This leads to his enrollment in an academy that trains 'Sacred Tree Knights'. As the academy's only 'Forbidden Curse User', Kurohiko's new life begins. Note: The book version is currently available in volumes 1-9. The web and book versions have some differences in content.