Sekai de Ichiban Yasashii Ongaku

Also known as: 世界でいちばん優しい音楽, The World's Most Tender Music, 세상에서 가장 아름다운 음악

by Mari Ozawa

A cute and touching story of a single mother, Sumireko, and her daughter, Nozomi. The manga starts off with Nozomi being sixteen years old in the first chapter, then hops back to before she was born. Finally with the third chapter starts the "real" story, when Non-Non (Nozomi) is three years old.