Just as every cultured Western household during the early 20th century was expected to have a piano in the parlor, almost all Japanese upper-class households, until well past World War II, had a koto. Training on this lovely 13-stringed zither, originally imported into Japan from China as part of the gagaku Imperial orchestra, was considered, along with proficiency in the tea ceremony, de rigueur for the well-bred young lady.
Until recently most women (and many men as well) had a familiarity with the instrument and the music. As recently as 30 years ago one often heard, walking through residential areas, the sonorous plunks of silken strings reverberating in the evening air.
Then came Yamaha. In the postwar economic boom, the company decided that pianos were the wave of the future and began mass-producing and mass-marketing them. Their ubiquitous music schools trained both piano students and teachers and insured that there would always be customers for their products.