is a Japanese light novel written by Hiro Yà «ki and illustrated by , with art and backgrounds by Momoka Nagatani. Kyoto Animation published the novel under their KA Esuma Bunko imprint in August 2018. An anime television series adaptation also produced by the studio, titled in English as Sparks of Tomorrow, is set to premiere in July 2026.
In Meiji era Japan, civilization is highly dependent on advanced steam power. Two individuals meet in Kyoto and uncover the secret of the "20th Century Electrical Catalog", allowing them the potential to realize the dreams they once had.
20 Seiki Denki Mokuroku is a Japanese light novel written by Hiro Yà «ki and illustrated by , with art and backgrounds by Momoka Nagatani. Kyoto Animation published the novel under their KA Esuma Bunko imprint on August 10, 2018 ().
On July 27, 2018, KA Esuma Bunko's Twitter account announced that an anime adaptation of the novel would be produced, and would be animated by Kyoto Animation, but the project's status remained unknown for years following the arson attack next year, which destroyed Kyoto Animation's main production office.
On October 25, 2025, Kyoto Animation announced during its "KyoAni no Sekai-ten" ("Meet the Worlds of KyoAni") event that the anime adaptation would be a television series, titled and known in English as Sparks of Tomorrow. It will be directed by Minoru à Âta, with series composition handled by , characters designed by Kohei Okamura, who will also serve as chief animation director, worldview setting handled by , and music composed by Hitomi Koto. The series is set to premiere on July 5, 2026, on Tokyo MX and other networks. Netflix will stream the series globally. The opening theme song is "Eureka Evrika", performed by Luna Goami, while the ending theme song is performed by Ginger Root.
20 Seiki Denki Mokuroku won an honorable mention in the full-length novel category at the 8th Kyoto Animation Awards in 2017. The entry was the only one to win any of the awards available that year.