Yu☆Gi☆Oh! Go Rush!!

Siblings Yuuhi and Yuamu Oudou run a small consultancy for alien trouble despite never having met a real extraterrestrial. Yuuhi is convinced that an alien stole something precious from him, so he refuses to stop searching. One day, a strange trail in the forest leads the pair to an actual spacecraft and to Yuudias Velgear, a visitor from a distant star cluster torn apart by a long war.

Yuudias believes Rush Duel may hold the key to ending the conflict in his homeland, even though he does not yet understand how the game works. The siblings agree to teach him, turning their first encounter with an alien into the beginning of a chain of duels and discoveries that suggests Yuudias's arrival on Earth was anything but accidental.