Two soldiers from warring countries are bound by a pledge as master and servant. Taki Reizen is a Commander of sublime beauty, shouldering the fate of his nation. Called "Mad Dog" because of his rough temperament, Klaus has sworn his loyalty to him as a knight. Despite this, those around them are cold and disapproving, full of various misgivings. For all their genuine feelings, what will come of love made cruel by the violence of war?

After swearing off music due to an incident at the middle school regional concert 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.

A special made before the rest of the KOR anime to test the possibility of making more. Essentially an alternate TV version of episode 46 , Kyosuke and Madoka go to the beach only to be trapped alone together.

After the TV-series of Kimagure Orange Road, Kyosuke and Madoka have finally arrived at the point where they are close to graduation and have to decide where they want to go to college. Naturally, they want to go together, so beside all the studying they also have to look for a proper college where they can enter both. Hikaru, still a year from graduating, wants to support Kyosuke as well and does that in her own way. But while she does that, Madoka feels jealous and tells her feelings to Kyosuke. And then Kyosuke has to take action to finally decide on the girl he loves... thus concluding the story of the Kimagure Orange Road.