Yu☆Gi☆Oh! Go Rush!!

Yuuhi and Yuamu Oudou are two siblings, who start working at Ultraterresterial Trouble Solutions, an alien hunting company inherited from their parents. Yuuhi is desperately determined to meet any alien as he believes these creatures have stolen his Earthdamar. Although they have not caught any aliens before. One day, they find a mysterious crop circle with a spaceship around fallen trees in a forest. They explore and meet with Yudias Velgear, an alien from the Velgear Star Cluster. Yudias asks them if they want to learn Rush Duel. Rush Duel is a kid-play game for elementary schools. Yudias believes this game can save its town from a drastic war. Yuuhi and Yuamu agree about it. Soon they all realize that their meetup is not a coincidence.