Does "your [Uta] cards" refer to my [Uta] Leader or [Uta] Characters?

It refers to both your [Uta] Leader and Characters.

[P-060] - Tot Musica (One Piece Promotion Cards: Starter Deck 11: Uta Deck Battle) - One Piece Card Game

[Main] You may rest 1 of your [Uta] cards: Rest up to 2 of your opponent's DON!! cards.

Market Price

USD 0.41

All time High (last 6 months)

USD 0.44

All time Low (last 6 months)

USD 0.33

3 stores currently have this card in stock.