Ginji — an 18-year-old struggling writer. The one who appeared before him was Nagare, the older sister who had left home five years ago.

Barely holding himself together at his father's house, Ginji has nowhere to go. Nagare quietly makes him an offer. A sudden cohabitation begins, neither knowing much about the other — two siblings slowly weaving words in a rain-soaked, grey city.

What is her true intention? Where will the two of them end up?