KakoPad: Nagaoka Hanabi Monogatari
Genres: Sci-Fi
Type: ONA, Episodes: 1
Aired: Dec 25, 2017
Source: Original
Rating: G - All Ages
Synopsis:
An educational web anime where an apathetic elementary student Yukita, who is visiting his grandfather along with his sister, clicks a mysterious app on his KakoPad. The two children are suddenly teleported back to August 1, 1945--the same date as the Nagaoka air raid.

The Nagaoka Fireworks Festival was founded in 1946. The event is in remembrance of those who died in WW2, specifically with the three shiragiku (white chrysanthemum fireworks) launched. The anime itself was commissioned by the foundation that organizes the Nagaoka Fireworks Festival. In 2003 and onward, the fireworks officially starts at 10:30pm, the same time the bombing began; and the duration of the short is 10min30sec long as well to mirror this very important time.