影片讲述个性有些内向消极的主人公纪子(桥本爱 饰)17岁到25岁的经历。纪子10岁的时候失去了母亲(宫崎葵 饰),而母亲早就知道自己余下的日子不多,于是约好在纪子二十岁之前每年生日都送她生日卡片。尽管纪子成长过程中经历了友情、恋爱和结婚等各种烦恼,但生日卡片一直是她的力量源泉,陪伴着她成长。Is the loss of one's mother at the age of ten made any less dismal if one receives letters from her once a year thereafter? Noriko loses her mother Yoshie and has to contend with life, friendships, love and marriage as well as her own personality as she grows up. Yet, she has the sage words of her mother to guide her.