New information has been released today for the upcoming Sound! Euphonium film, the first of this being a key visual which can be seen above. A teaser can be seen later in the article as well which also reveals the opening date for it which is confirmed for April 23rd. The movie mind you will be “Sound! Euphonium the Movie: Welcome to the Kitauji High School Band Concert”. It is said the film will be looking back at the first season anime series and a second season will continue directly afterwards. The series itself is based off of a original novel made in 2013 by Ayano Takeda. A manga adaption would later release on November 28th 2014 and end October 30th 2015 with 3 volumes releasing for it. Its first season would later be released April 8th 2015 and end July 1st 2015 airing 13 episodes. Other spinoffs and specials have also been released for the anime series.
Regarding the film starting on December 19th the 39 participating theaters will be selling advanced tickets for the upcoming film. If you purchase these tickets you will get one of four random clear file folder with art of the characters, this can be seen below:
A plot summary of it can also be seen for it below quoted from MAL:
After swearing off music due to an incident at the middle school regional brass band competition, euphonist Kumiko Oumae enters high school hoping for a fresh start. As fate would have it, she ends up being surrounded by people with an interest in the high school brass band. Kumiko finds the motivation she needs to make music once more with the help of her bandmates, some of whom are new like novice tubist Hazuki Katou; veteran contrabassist Sapphire Kawashima; and band vice president and fellow euphonist Asuka Tanaka. Others are old friends, like Kumiko’s childhood friend and hornist-turned-trombonist Shuuichi Tsukamoto, and trumpeter and bandmate from middle school, Reina Kousaka.However, in the band itself, chaos reigns supreme. Despite their intention to qualify for the national band competition, as they currently are, just competing in the local festival will be a challenge—unless the new band advisor Noboru Taki does something about it.From the studio that animated Suzumiya Haruhi no Yuuutsu, Kyoto Animation’s Hibike! Euphonium is a fresh and musical take on the slice-of-life staple that is the high school student’s struggle to deal with their past, find romance, and realize their dreams and aspirations.