If the hand of my opponent is full and I want to exile this card, while it has enough mana (don’t know the proper name of the ability, german player), the creature is not destroyed, since it isn’t able to be retourned. Otawara is exiled, but my opponents creature is still on the battlefield.
But as I read the card (in german) the creature should be bounced or destroyed. There’s no “if your opponent has 5 or less cards in his hand” clause.
