The fourth and the final novel of the Hibike! Euphonium series titled Hibike! Euphonium Kitauji Koukou Suisougaku-buno no Himitsu no Hanashi(け! ユーフォニアム 北宇治高校吹奏楽部のヒミツの話Hibike! Euphonium : Kitauji Kōkō Suisōgaku-bu no Himitsu no Hanashi , lit. Sound! Euphonium: Secret Story of Kitauji High School's Wind Ensemble) was released on May 25, 2015. This volume is the collection of short stories. Some take place during or between the event of volume 1,2 and 3 and some take place after the end of volume 3.