Satoshi moves to Tokyo to attend university, and when he goes to say hello to his neighbor, he discovers that the person living next door is his mother, who disappeared when he was little! The two are confused by this sudden reunion, but his mother, Kiriko, This chance reunion leads to an attempt to repair the relationship between mother and son, but the gap that has existed for so long is not easily bridged, and Kiriko feels lonely when her son no longer calls her "mother." So she takes action...