Fubo Hayashi was the primary pen name of the Japanese writer Kaitarō Hasegawa, a novelist active in the early Shōwa period who created the iconic swordsman character Tange Sazen, a figure later adapted extensively into manga, film, and television. Born on January 17, 1900, on Sado Island in Niigata Prefecture, his background was shaped by a peripatetic early life. After time in Hakodate, he traveled to the United States around 1917, studying at Oberlin College and working various jobs, including as a cook, before returning to Japan in 1924.

Upon his return, Hayashi established a distinctive literary career by writing under three separate pen names, each serving a distinct genre and persona. As Tani Jōji, he wrote humorous and cosmopolitan fiction based on his American experiences, notably the Meriken Jappu series. Under the name Maki Itsuma, he produced true-crime mystery stories. As Hayashi Fubō, he focused on semi-historical period fiction, and it is under this name that he created his most enduring character.

Hayashi’s creation of Tange Sazen began in 1927 with the serialized novel Shinpan Ōoka Seidan, which ran in the Mainichi Shimbun from October 1927 to May 1928. In this initial appearance, the one-eyed, one-armed swordsman was introduced as a supporting character. The character’s dramatic appearance, often enhanced by striking illustrations, captured the public’s imagination to such a degree that multiple silent film adaptations were produced within the year. The overwhelming popularity of these films led Hayashi to write a new serial simply titled Tange Sazen, which ran from 1933 to 1934 and recast the character as the central hero, evolving from a nihilistic rōnin into a fighter for justice.

The character of Tange Sazen became a foundational figure in Japanese popular culture. The original stories have seen a long and significant adaptation history, particularly in cinema, with dozens of film versions produced. The first silent films appeared in 1928, and the character became a signature role for actor Denjirō Ōkōchi in numerous sound films throughout the 1930s. The work also holds a notable place in the history of manga. While Hayashi was a novelist and not a manga artist himself, his original story was adapted by Osamu Tezuka, the "God of Manga." Tezuka’s manga version, titled Tange Sazen, was published as a supplement in December 1954, cementing the character’s legacy in the medium and introducing it to a new generation.

Recurring elements within Hayashi’s work as Fubo Hayashi center on the popular jidaigeki (period drama) genre. The Tange Sazen stories are defined by the protagonist’s striking physical disability—missing an eye and an arm—which becomes a central aspect of his identity as a cynical, masterless samurai. His artistic identity is characterized by a remarkable versatility, demonstrated by his ability to maintain three distinct literary careers under separate pseudonyms. His output ranged from historical fiction to contemporary cosmopolitan tales and true-crime narratives, showcasing a broad talent that drew heavily on his international experiences and keen observation of both Western and Japanese society.

Fubo Hayashi’s significance to the Japanese entertainment industry lies in his creation of one of its most enduring archetypal heroes. Tange Sazen stands alongside other legendary figures as a staple of Japanese cinema, television, and manga. The immediate and prolific film adaptation of his work in the late 1920s also illustrates the early synergy between popular literature and the burgeoning film industry in Japan. Hayashi died young on June 29, 1935, at the age of 35, due to acute bronchial asthma, but his creation has ensured a lasting legacy.