Researcher and illustrator Renato Rivera Rusca reported on Twitter on Saturday that at a screening of the Belladonna of Sadness anime film in Tokyo on the same day, the organizers of the event stated that director Eiichi Yamamoto passed away on September 7. He was 80.

The event planning company Anime Novecento also confirmed the news, and stated that the family of Yamamoto happened to see news about the event on social media, and contacted the organizers to confirm that Yamamoto had passed away. His funeral on September 12 was limited to close relatives only.

Yamamoto was born in Kyoto in 1940. After graduating high school he joined Ryuichi Yokoyama's Otogi Productions studio. He met Osamu Tezuka in 1960 and joined Mushi Productions one year later. There, he co-directed Mushi Productions' first work, Tales of the Street Corner, with Yûsaku Sakamoto. He then served as an animator and episode director for Astro Boy in 1963, and directed Kimba the White Lion in 1965, the Jungle Emperor Leo film in 1966, and A Thousand & One Nights in 1969. He directed the Cleopatra film in 1970 along with Tezuka, and then directed Belladonna of Sadness in 1973. He also directed the Wansa-kun television anime in 1973.

After Mushi Productions declared bankruptcy, Yamamoto worked for Yoshinobu Nishizaki, writing scripts and supervising the original Space Battleship Yamato (Star Blazers) television anime series. He also designed the logo for the anime. He also supervised the Urotsukidoji: Legend of the Overfiend OVA.

Yamamoto released a book in 1989 titled Mushi Pro Kōbōki: Ani Meita no Seishun (The Rise and Fall of Mushi Pro: The Youth of Ani Meita), which is a semi-fictionalized but autobiographical account of his time at the studio.