Oume & Otane are basically Oume Goketsuji and Otane Goketsuji with each other strapped to their backs, which is how they appeared in Groove On Fight. Since Oume decided to share the position of Clan Leader with Otane, this meant that both sisters would have to fight in the tournament together as one person, rather than fight separately. To make up for this, Falco was chosen to be their partner.