After a fatal encounter with a truck, Takafumi Takaoka's uncle, Yousuke "Ojisan" Shibazaki, lies comatose for 17 years. When he finally regains consciousness, Ojisan begins to ramble in a foreign tongue and reveals that he had been transported to a magical world called Gran Bahamal. Takafumi dismisses his uncle's claims as nonsense until an incantation makes a cup of water hover in the air. In a flash of brilliance, the pair creates a YouTube channel to showcase Ojisan's magical abilities. The responsibility now falls on Takafumi's shoulders to acquaint Ojisan with everything that has transpired during his absence, including getting him up to speed with the internet, new technology, and surprisingly, the outcome of the '90s console war—the result of which was especially distressing for a hardcore SEGA fan. With Ojisan's wisdom from his other world experiences, they grow their YouTube channel and tackle online comments and trolls. The journey of this uncle-nephew duo promises to be anything but conventional.

Since ancient times, shrine maidens who wield swords have been exorcising "aratama," strange existences that threaten the human world. These young women who wear school uniforms and a sword are called "Toji," and they serve as an official unit within the police force as a "special religious service police squad." The government authorizes the Toji to wear swords and serve as government officials, and the government has set up five schools throughout the country for the girls to attend. In the spring, the five schools send their best Toji to compete in a tournament. As the tournament comes closer, all of the representatives rigorously train themselves in order to get stronger and improve their skills.

A foreign transfer student from the city arrives one day in a Japanese country town. Enchanted by his air of mystery, his classmates nickname him "Matasaburou the Wind Imp" after a local legend. Eventually they become friends and spend many days playing in the countryside. One windy day, Matasaburou returns to the city, leaving his classmates to speculate that he really was Matasaburou the Wind Imp and that he flew away on the wind.

The war between the Heike clan and the Genji clan continues. This time, Nozomi has to fight a powerful supernatural enemy and make a choice: protect her friends and stay by Kurou's side, or choose her first love, Masaomi, which is the leader of the Heike, and her enemy.