The year is 1274. After conquering most of the known world, the Mongols turn their sights on Japan and their first step on the road to a full invasion of the mainland is taking Tsushima Island. Kuchii Jinzaburou and a group exiles are sent by the Kamakura Shogunate to the island at the request of Princess Teruhi. There they will face overwhelming odds and the fate of Tsushima will be decided!

In the year 2043, , the world's first successful full-dive VRMMO was released. In addition to its ability to perfectly simulate the five senses, along with its many other amazing features, the game promised to offer players a world full of infinite possibilities. Nearly two years later, soon-to-be college freshman, Reiji Mukudori, is finally able to buy a copy of the game and start playing. With some help from his experienced older brother, Shuu, and his partner Embryo, Reiji embarks on an adventure into the world of . Just what will he discover and encounter in this game world known for its incredible realism and infinite possibilities? (Source: J-Novel Club)