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.

The game features several mechanics not found in the Prologue game including:

80-120 hours of gameplay depending on the player.

Equipment upgrading.

Monster Taming.

Class change.

Enemies level up with you, and learn new skills at higher levels.

Rank up in the Guild to get stat boosting cards.

A massive world map with several methods of travel including Airship, Teleportation Items, and a Guild Teleporter.

Quest Notes for tracking side and main quest objectives.

A World Map and a Local Map to track your position in the world for easier travel.

Learn skills from Skill Cores instead of through leveling.

A difficulty option for those that want to sail through the game, and those that want an extra challenge.

And much more!