Sawa and her son, Satoshi, live alone in a mother-son household. Sawa works as a caregiver for Ryūya, a classmate of Satoshi's, looking after his bedridden grandmother who works overseas. Sawa's daily visits cause Ryūya, who is going through puberty, to begin looking at her strangely. Unable to bear it any longer, Ryūya finally breaks down and forcibly hugs Sawa. When Satoshi discovers this…