American Isekai: Legends of Nipponia

250 years ago, on the world of Nipponia, twin siblings Taneela and Tanaka seek to become Adventurers like their father. On the day of their registration, they are contacted by Mavis, the Crystal being and guardian of the world. Can they gather enough forces to stand against the rising evil in their world? This is the story of how two unlikely heroes set off to save a world, and how the story of American Isekai began.