Before World War II, Ikenami worked as a stockbroker in a Tokyo company, laying the groundwork for his future endeavors. Later, he became a pupil of the esteemed Shin Hasegawa theatre script studio, where he honed his skills and refined his craft. This experience ultimately led him to decide on a new path, and he began to pursue a career as a novelist.
Ikenami was an incredibly prolific writer, and his works began to gain recognition in the 1950s. Several of his novels and stories were adapted into movies, with the first being "Fighting Spirit Tear of Nayoroiwa" in 1956. This marked the beginning of a long and successful career in film adaptation.
One of Ikenami's most notable and enduring works is the novel-river "Sanada Taihei-ki", which was initially serialized from 1974 to 1983 in the "Weekly Asahi". This series showcases Ikenami's remarkable storytelling abilities and his capacity to craft engaging narratives.
In addition to his literary pursuits, Ikenami also created the "Ikenami Shotaro Sanada Taiheiki Museum", which is located in the heart of Ueda City. This museum serves as a testament to Ikenami's legacy and features exhibits related to his works, including books and manuscripts.
Among Ikenami's most famous novels is undoubtedly "Koroshi no yonin" (Master Assassin),also known as "Hissatsu shikake-nin". This novel has been adapted into several films and television series, including an ABC TV series from 1972, directed by renowned directors such as Kinji Fukasaku and Kenji Misumi, and starring Ken Ogata as the protagonist, Baian Fujieda. The novel was also adapted into three films in 1973-74, with Jirô Tamiya and Ogata himself playing the lead roles.
In 1981, Yasuo Furuhata directed a new film version of the novel, "Shikake-Nin Baian" (Professional Killer Baian),starring Kinnosuke Nakamura and Juzo Itami. Fuji TV also produced a new television series based on the novel, which premiered in 1982 and starred Keiju Kobayashi (and later Ken Watanabe) as Baian.
Ikenami's only original script for a film was written in 1960, demonstrating his versatility and range as a writer.
