Mizusaki Keita, a chef at a French restaurant in the shopping district, is in a state of despair after his beloved wife is predeceased by illness, but with the support of Kataoka Miho, a pastry chef apprentice who works at the restaurant, he decides to reinvent his wife's memorable piano as a street piano. Meanwhile, famous pianist Imanishi Kohei, who is said to be a rising star in the piano world, suddenly appears asking him to play the street piano. Kohei leaves when he finishes playing the perfect "Nocturne". Why did he come to the shopping street to play the piano? Through a street piano placed in a French restaurant in a shopping street, various stories are born.
