Noboru Kuroda is a 13-year old boy who believes that life is empty and meaningless. He finds a hole into the wall between his room and his mother's room and uses that to spy on her. He kills a kitten with a group of friends who share his worldview and feels that the act was transformative. He sees Ryuji as a hero and a real man—until he gives up the sea and is soft about punishing Noboru when they find the hole in the wall. Then Noboru complains to his friends. Together, they decide to drug and kill Ryuji.

Fusako Kuroda is Noboru's mother. She is young and widowed. Fusako works hard and enjoys tennis and embroidery. She falls for Ryuji, a sailor, but isn't sure whether she wants to be in the relationship. She doesn't want to constantly be left by him when he returns to the sea. When he proposes, she happily accepts.

Ryuji Tsukazaki is a sailor who falls for Fusako. He's torn between a life on the land and the romance of the sea. His love for Fusako and the repetitiveness of a life on the ship lead him to offer her his money and his hand in marriage. She agrees. However, Noboru is offended by his actions and disappointed in him. Ryuji is led by the boys to the sea where he talks about his dreams and drinks the poisoned tea they drugged.

The Chief is a friend of Noboru's and the leader of the gang of boys. He's the one who dissects the kitten and the one who decides that the boys need to ultimately murder and cut Ryuji apart at the end of the story.

Ryuji Tsukazaki

Ryuji Tsukazaki, a sailor and Fusako Kuroda’s lover. Having crossed the seas countless times on a freighter, Ryuji is thoroughly at home on the ocean and enjoys his work but lately has had passing thoughts of settling permanently on land. He also sees himself as destined for some kind of glory, although he cannot yet define in his own mind what kind of glory he will receive. He meets Fusako Kuroda and her son Noboru and becomes her lover, as well as a hero figure for the son, who is fascinated with his strength. Ryuji and Fusako decide to get married; he further determines to retire from the sea and work for her in the fashion boutique that she owns. Ryuji’s determination to retire from the sea enrages her son, Noboru, who wants Ryuji to retain his hero status by remaining primarily at sea. Ryuji finally receives his ironic “glory” by means of a painful death at the hands of Noboru and his friends, who seek to punish him.

Noboru Kuroda

Noboru Kuroda, a thirteen-year-old boy and the son of Fusako Kuroda. Noboru, like his friends, is a nihilist who believes that there is little meaning in life; nevertheless, he is fascinated with the strength and vastness of the sea and with Ryuji, who lives on and in the sea. Noboru believes that Ryuji partakes of the sea’s strength. When Ryuji becomes Fusako’s lover, Noboru is delighted, seeing direct links between himself and his mother, his mother and the sailor, and the sailor and the sea. Through this linkage to the sea and his general fascination with the strength of the sailor, Noboru begins to see some significance in his own life. When the sailor retires from the sea and exhibits “weak” behavior, such as working in a dress shop, he is no longer of heroic stature in Noboru’s eyes, and the psychic linkage of the boy to the sea is broken. He is infuriated and decides to punish Ryuji for “falling out of grace” with the sea. The punishment is a ritualistic murder of Ryuji.

Fusako Kuroda

Fusako Kuroda, Noboru’s mother, a widow and owner of a clothing boutique. A very lonely woman since the death of her husband, Fusako occupies herself at her shop. When the sailor, Ryuji, comes into her life, the vacuum is filled, and she happily looks forward to marriage and a classic suburban domestic life with her new mate. She is completely unaware of her son’s strange, nihilistic bent, and she unwittingly draws her intended husband to his death by attracting him to a domesticated but unheroic existence on land. She reflects the author’s own distaste for the unimaginative middle-class mentality, and she is left a pitiful figure at the end, unaware of what will become of her fiancé and of the awful deed perpetrated by her son and his friends.

The Chief

The Chief, a thirteen-year-old boy, Noboru’s friend and leader of their six-member gang. The Chief is the instructor in nihilism for the boys. He spends his time at their meetings enlightening them on the meaninglessness and chaos in the world, directly reflecting the author’s own views. He makes Noboru kill a kitten and then proceeds to dissect it to show the gang that there is nothing sacred or magic about a living being. It is the Chief who suggests to Noboru that killing the sailor would be an appropriate way to punish him and to return the sailor to his heroic status.

On the surface, Noboru is a normal thirteen-year-old boy. He is a good student, obeys his mother as much as any teenager does, dreams of having adventures, and likes to be with his friends. Underneath, however, Noboru harbors some disturbing qualities and philosophies: He is convinced that he is a genius; he believes that death is mankind’s only goal; he believes that authority is an enemy; and he practices “hard-heartedness” as a matter of pride. His obsession with the sea leads him to think of his heart as a “large iron anchor” which resists decay. He believes that the sea holds some sort of answer for him that his “empty world” on land cannot provide. When he meets the sailor Ryuji, he sees in him a mythological hero who follows the sea and answers only to the wail of the ship’s horn. The sailor represents beauty, glory, danger, perfection, and death, and Noboru is drawn toward what he considers a “universal order.” Nothing else will do.

As for Ryuji, he has many of the same passions as Noboru: beauty, glory, danger, and a love of the sea. He also feels the power of death tied up in his dreams, but adds to that the power of a woman. Feeling destined for glory by the time he was twenty, Ryuji left the unflexibility of land for the mysteries and movements of the sea. Yet nothing ever happened. Even the dangers of storms at sea and the exotic ports he visited soon became routine. Now he uses a woman and sexual love as a substitute for the sea and glory. As a result of this compromise, the sailor dies a fallen hero.

The Chief, a self-appointed philosopher, preaches to the gang about the chaos in the world, the need to return internal or universal order to mankind, and the necessity of gaining control over death. He is the one who sets up the bizarre rituals. His self-control and contempt for the world around him are so strong that he has no trouble leading his gang in either their ideas or their actions.

The woman who lures Ryuji from the sea is Fusako. She is a modern and very Westernized Japanese woman. Most often she is described through her physical surroundings and activities: a house without one traditional Japanese room; a clothing boutique specializing in expensive, Western-style fashions; her own clothes, cashmere sweaters, silk stockings, fur coats, tennis outfits; her habits of smoking in public and running her own business; and her indiscretion at taking a lover.