Noguchi's daughter Midori died at the age of just 7 days in 1908. In the Meiji period, the infant mortality rate was quite high, with about 20–30 percent of children dying before reaching schooling age. It was common to have many children to aim for success of the household, but Noguchi was divorced and thus mourned the loss of his only child for a long time.
It is widely believed that Noguchi wrote this poem upon seeing the girls in his village play with bubbles, being reminded of the brief existence of his daughter. However, other than the above facts, the direct inspiration for the song is unknown.[1][2]