One major theme is seppuku. This is a performative ritual suicide (which involves incising the abdomen, sometimes in ritual attire), traditionally practiced by defeated samurai, but later practiced by laypeople in Japan. This act was outlawed in 1873, though many (especially in the tumultuous decade of the 1930s) continued to practice it. Perhaps one of Mishima's aims in publishing the story was to highlight and romanticize a forbidden tradition that, in practice, refused to die. The author Mishima himself publicly committed suicide after failing to inspire a coup among the Japan Self-Defense Forces.

Another theme is that of love. Lieutenant Shinji Takeyama and his wife, Reiko, are the epitome of a committed couple. In a description of a photograph of the couple, Mishima explains that, "After the suicide, people would take out this photograph and examine it, and sadly reflect that too often there was a curse on these seemingly flawless unions."

At the time of the lieutenant's decision to commit suicide, Reiko has been his wife for less than a year, and yet she unwaveringly and immediately resolves to join him. Elsewhere, Mishima explains that "a woman who had become the wife of a soldier should know and resolutely accept that her husband’s death might come at any moment." Mishima's attitude toward love is a very traditional but romantic one; men and women who were truly in love were understood to be joined in death as readily as in life.