Since the early 20th century, Japan has been quick to embrace Western music. As a result, most of the songs known by Japanese children today have been influenced by Western music or are the result of adding Japanese lyrics to the melodies of non-Japanese songs. Many modern songs produced by adults and the mass media are quite different from traditional folk songs – in particular, warabe uta, shōka, and dōyō – that Japanese children have been singing for centuries. In this chapter, I will briefly introduce the history of traditional Japanese songs while also showing how traditional songs have been preserved in children’s play to this day. I will further discuss the importance of children’s motivation in relation to improvisational activities. In a series of interviews, I asked several 5–6-year-old girls about their musical preferences and how they enjoy improvising. In addition to reviewing their responses, I will examine the lyrical and melodic characteristics of songs they improvised, showing how they used long tones, extended sounds, and rising pitches. I will also explore the relationship between these children’s musical experiences and their improvisational spontaneous singing. Finally, I will show how the children create songs using off-beat rhythms and other musical qualities that appear to be strongly influenced by J-Pop, anime, and other modern media that the children are exposed to at home.