Nankichi Niimi is recognized as the original creator behind several anime works, most notably the 2011 short film O-jii-san no Lamp. He was not an animator or manga artist but a celebrated Japanese author of children's literature whose stories have been adapted into anime, primarily as the original source material. His real name was Shohachi Niimi, and he was born on July 30, 1913, in what is now the city of Handa in Aichi Prefecture, Japan. His childhood was marked by loneliness following the death of his mother when he was four years old. He displayed literary talent from an early age, writing haiku and children's stories while in junior high school.

Niimi began his writing career by submitting children's songs and stories to notable magazines such as Akai tori (Red Bird). He achieved early success with the publication of his most famous work, Gon, the Little Fox (Gongitsune), at the age of 18. He later moved to Tokyo to study English literature at the Tokyo University of Foreign Studies, but after graduating, he fell ill with tuberculosis and was forced to return to his hometown. He worked as a teacher at a girls' high school while continuing to write. In 1942, he published his first collection of children's stories, titled Ojiisan no ranpu, which provides the source material for the anime O-jii-san no Lamp. His life was cut short when he died from tuberculosis on March 22, 1943, at the age of 29.

While Niimi was not a direct producer of anime, his literary works have served as the foundation for numerous anime adaptations. Several films, television specials, and television series episodes have been credited to him as the original author. These include the 1979 television series Nihon Meisaku Douwa Series: Akai Tori no Kokoro and Manga Kodomo Bunko from 1978 to 1979. A notable film adaptation is Gongitsune from 1985, based on his seminal story. More recently, his work was adapted for the 2011 short film O-jii-san no Lamp, produced as part of the Young Animator Training Project. In all these productions, his role is consistently listed as the original creator or author of the source work.

The artistic identity of Nankichi Niimi is defined by the recurring themes found within his literature. His stories are known for their detailed and accurate depictions of rural Japanese life, often set against the backdrop of his own hometown. Common themes include loneliness, the meeting of hearts in the midst of sadness, and the beauty of life, often conveyed with a blend of humor and pathos. The sense of loneliness and sadness from his own childhood is said to have deeply influenced his internal world and is reflected in his writing. His most iconic character, the orphaned fox Gon from his signature story, is often interpreted as a parallel to his own life. His works are celebrated for their rich sense of story and their ability to convey universal emotions, making them a staple of Japanese elementary school textbooks for decades.

Niimi's significance to the anime industry is primarily as a source of classic, emotionally resonant narratives that have proven adaptable for the screen. He is not an industry figure in the sense of a director or producer, but rather a foundational literary figure whose legacy continues to provide source material for new productions. He is sometimes called the Hans Christian Andersen of Japan, a testament to his stature in the world of children's stories. A memorial museum dedicated to his life and work stands in his birthplace of Handa, preserving his manuscripts and personal effects. His continued relevance was highlighted when Empress Michiko of Japan mentioned one of his stories as having left a deep impression on her in her childhood. Through anime, his classic tales from the early 20th century are introduced to new generations and international audiences.