Natsumi, overcome with loneliness after losing her husband, ended up crossing the line with her son Hiroaki. As a result, their mother-son relationship gradually unraveled. Several years later, Natsumi is on the verge of remarrying a man she met at work. One day, after seeing a honeymoon brochure, Hiroaki says, "I'd like to go on a trip with you, Mom." His words shock Natsumi, bringing back memories of their past. Hiroaki, too, has never forgotten that day and continues to harbor forbidden feelings for his mother. A story filled with hope as the bond between mother and son begins to stir once again.