Saki worries about her younger brother Mamoru, who has seemed down lately. She learns he’s being bullied at school and still doesn’t even understand the meaning of sex. When Mamoru confesses his feelings, Saki gently tells him, "We can't do anything intimate as siblings." However, after a certain incident involving Mamoru at school, Saki resolves to wholeheartedly help her beloved little brother in every way she can. This title captures the warmth and purity of her feelings, and how they ultimately come to be expressed.