Yu-Gi-Oh! GO RUSH!!

After taking over their parents' company, siblings Yuuhi and Yuamu Oudou begin working at the Alien Trouble Consultancy, an agency dedicated to tracking down aliens. Though neither has ever seen an alien before, Yuuhi is obsessed with finding one-convinced that an extraterrestrial stole his prized possession, the "Earthdama." During one of their searches, the siblings stumble upon a bizarre scene in the forest where fallen trees form a pattern resembling a crop circle. Investigating further, they find a strange spaceship and, driven by curiosity, step inside. There, they encounter Yuudias Velgear, an alien from the Velgear Star Cluster. To their surprise, Yuudias is desperate to master Rush Duel, a card game popular with kids, believing it holds the key to ending his homeworld's endless war. Agreeing to teach him, the siblings soon suspect their meeting with Yuudias wasn't just chance.