Yuuhi Oudou

Yuhi is energetic, impulsive, expressive, and stubborn. He tends to rush directly into situations rather than analyzing them first, creating a sharp contrast with Yuamu's more calculated approach.

His fascination with aliens is intensely personal. After having his Earthdamar stolen, Yuhi becomes determined to prove the existence of extraterrestrials and recover what was taken from him, even when other people dismiss his claims.

Yuhi also loves Rush Dueling and takes pride in his own style. He is not always as technically accomplished as Yuamu, but setbacks rarely keep him down permanently, and his persistence becomes one of his defining qualities.

Yuhi uses a Jointech Deck composed primarily of EARTH Machine monsters. The archetype reflects his enthusiasm for machines by combining mechanical concepts into unusual hybrid designs.

Jointech Rex is his principal ace. His strategies use Machine monsters, Graveyard resources, and supporting cards to create opportunities for his larger Jointech monsters.

Yuhi also possesses an unusual connection to extraterrestrial phenomena. His distinctive hair can react to nearby aliens, effectively functioning as an alien detector even though Yuhi himself does not initially understand that ability.

Yuhi and Yuamu operate UTS, the Ultraterrestrial Tracker Squad, in Mutsuba Town. Yuhi occupies the company's lowest rank despite being one of the siblings responsible for its creation, while Yuamu handles its leadership and business operations.

Their search for extraterrestrials leads them to Yudias, providing definitive proof that Yuhi's claims about aliens are correct. Yuhi and Yuamu agree to teach Yudias Rush Dueling, while the Velgearian begins working for UTS.

The mystery of Yuhi's missing Earthdamar soon connects his personal search to the larger extraterrestrial conflict surrounding Yudias. Zuwijo is revealed to have taken the Earthdamar, and its unusual properties become increasingly important to the plans involving Earth, the Velgearians and Duel Monsters.

Yuhi's role expands far beyond his original alien hunt as he becomes directly involved in conflicts spanning planets and different periods of history, while his relationship with Rush Dueling repeatedly changes in response to the consequences he witnesses.

Yuamu Oudou is Yuhi's twin sister and the president of UTS. Yuamu Oudou frequently outthinks and outranks her brother, but the siblings remain close partners throughout their investigations.

Yudias Velgear is the alien whose arrival finally proves Yuhi's belief in extraterrestrial life. Yuhi becomes one of Yudias Velgear's first Earth friends and helps teach him Rush Dueling.

Zuwijo Zwil Velgear becomes closely connected to the mystery that originally drove Yuhi's alien investigations. [Zuwijo Zwil Velgear is responsible for stealing Yuhi's Earthdamar, drawing Yuhi directly into the larger Velgearian conflict.](#spoiler)

Manabu Sougetsu initially clashes with Yuhi and the other UTS members through his work monitoring extraterrestrials, but their repeated encounters bring them into the same wider group.