In April 1891 Karl Valts approached Tchaikovsky with the idea for an opera-ballet on the subject of the Japanese fairytale Watanabe (Ватанабе) (ČW 466) . Valts prepared the scenario and also completed the libretto . Tchaikovsky appeared enthusiastic about the idea, albeit with some important reservations, as he wrote in June 1891:
I have read through Watanabe with the most intense delight. It is an enchanting subject, extremely poetic and at the same time full of effects. It is with the greatest pleasure that I am willing to write the music for it, but on the following conditions: 1) Watanabe must be a ballet-féerie and not an opera-ballet. I simply cannot accept or understand that indefinite and unappealing artistic genre which goes by the name of opera-ballet. It must be one thing or the other: either my characters will sing, or they will mime. To have them do both at the same time is quite inconceivable for me. Now as an opera, Watanabe is an unsuitable subject for me, since I am prepared to allow the fantastic element in opera only insofar as it does not prevent the action from being carried by real, ordinary people, with their simple human passions and feelings. But there is just no way I can have a Sun Prince singing. For it is only people who can sing—and, if you wish, also angels and demons who intervene in human affairs on an equal footing with people. Besides, Watanabe, Ga-tani, and Nao-Shik are beings who in my view lie outside the real world, and I really can see no other way of portraying them truthfully other than in a symphonic manner. That is why I regard Watanabe as an excellent ballet subject, and for this uncommonly well-chosen and outlined subject I am willing to write music that shall be as good as I can make it. .