In the Kunitsu Gami play, Soh holds the hand of the Maiden and dances the Kagura with her (in the Japanese it's said they dance the Kagura) but in-game/ads, only Yoshiro is said to 'dance' and do the Kagura.
Soh's fighting style is meant to double as a complimentary dance to Yoshiro. They are actually dancing the Kagura together.
Or you could say it's a hint at them being one.
Yoshiro dances, Soh dances but Yoshiro is the only one dancing in the end.
Yoshiro dances, Soh dances but Yoshiro is the only one dancing in the end.
EDIT: Soh can dance the Kagura because Soh is the previous Maiden/Yoshiro! Not because they're one. Or are they still one? Hmmm.