From the latter half of the 1970s, Takemitsu created many works with titles related to water, such as "Rain" and "Sea." Takemitsu regarded "rain" and "sea" as temporary forms given to water, which itself is formless. He stated that music, too, is something to which a composer gives a temporary form, to sounds that are inherently formless. It can be said that this series of "rain"-related titles uniquely demonstrates Takemitsu's earnest attitude towards composition.

The piece begins with a phrase where the not-so-fast sixteenth-note movements in both hands seem to depict tree leaves dripping raindrops. Three distinct types of accents and detailed pedaling instructions create an extremely delicate and serene sound, while also expressing a sense of subtle movement. Broadly speaking, this work, which has an A-B-A form, is constructed from intricate passages played by the left and right hands with subtle, irregular displacements, and deep chordal movements. Furthermore, in the middle and concluding sections of the piece, fermatas appear with the instruction "dying away," extending the sound to the very limit of its decay, imbuing the work with a rich sense of fullness. It can be said that this is a suitable work for performers to undertake as a discipline, to listen intently to the sounds they produce and how those sounds fade away.