Shuji Sugiyama is a salaryman who, like so many others in postwar Japan, follows the same routine day after day: a crowded commuter train to his office in central Tokyo, long hours at work, and evenings spent with his colleagues. Married to Masako for eight years, the couple continues to bear the emotional weight of losing their only child, a tragedy that has left an unspoken distance between them. When a new relationship begins to disrupt this fragile balance, both he and Masako are forced to confront the consequences of their choices and reconsider the true meaning of marriage, responsibility, and companionship.