Short answers, pulled from the story.
Oten Shimokawa was a Japanese artist and political cartoonist who is considered one of the founding pioneers of anime. He directed Imokawa Mukuzo Genkanban no Maki in 1917, which is regarded as the first true anime film because it was the first Japanese animation to be publicly shown in a theater.
Shimokawa used chalk and white wax on dark board backgrounds, rubbed out portions of drawings to create movement, and drew directly onto film with ink, whiting out animated sections. These methods were developed partly to work around the high cost and scarcity of celluloid cels, which had to be imported into Japan at the time.
Shimokawa's first animated film was Imokawa Mukuzo Genkanban no Maki, released in 1917. The film ran for approximately five minutes and is considered the first true anime because it was the first Japanese animation to be publicly screened in a theater.
None of Shimokawa's films have survived. No copies of Imokawa Mukuzo Genkanban no Maki or any of his five other short films are known to exist, which is consistent with the fate of most animation made in Japan before the mid-1920s.
Shimokawa made six short animated films, all released in 1917. They include Imokawa Mukuzo Genkanban no Maki, Dekobō shingachō, Chamebō shingachō, two further Imokawa Mukuzo entries, and one additional short.
Chronic health problems ended Shimokawa's career as an animation director. He later worked as a consultant and editor for production companies making animated films during the 1930s and 1940s.