Shioda Tetsuya lived a boring life without ambitions and motivation. He had neither a girlfriend nor a job. His life was suddenly cut short by hopelessness and a serious disease Chuuni as his family didn’t need such a problematic guy. In his last days, Shioda dreamed to have a chance of changing his lifestyle.
Luckily a 33 years old virgin could transform into a young lady Tilea in a new universe. Tilea was happy while living in a nice family until her little sister was affected by the same malady. Her behaviour became weird and the girl called herself a Demon General who loyally served to a lineal offspring of the Three Great Demons named Demon King Zorg. Her mind seemed to be obsessive about the idea, so Tilea had to do something to stop the disease progression. Her efforts turned into a wish to depose Demon King from the throne. This controversial story retells about a hero who acted like a traitor in a search of benefit. Though the sister really belonged to one of the Six Demon Generals, Tilea used her condition as a reason for dominion.