__Instrument:__Alto Saxophone.
Chikai is a first year student during Kumiko's first year.

Spring in the first year of high school. Kumiko, a member of the brass band in junior high school, visits the high school brass band club with classmates Hazuki and Sapphire. There, she comes across Reina, her former classmate from junior high. Hazuki and Sapphire decide to join the club, but Kumiko can’t make up her mind. She recollects her experience with Reina at a competition in junior high school. 
 
(Source: Pony Canyon USA)

The third season of Hibike! Euphonium.
 
Kumiko's third year finally begins! With the concert band at Kitauji High School over 90 members, Kumiko is now the president and does her best with her final high school club activities to try to win her long-desired gold at nationals.
 
(Source: Crunchyroll, edited)

The next piece begins! Kumiko is now in her second year at Kitauji High School, and with a new year comes new problems. As if making it to Nationals wasn't hard enough, Kumiko is tasked with mentoring the concert band's troublesome first years – each with their own distinct personality and problems to solve. With Kumiko busy juggling both the concert band and her new role as senpai, how does her relationship with Shuuichi fit into the picture? 
 
(Source: Shout! Factory)

Students and best friends Mizore Yoroizuka and Nozomi Kasaki prepare to play a complex musical duet, Liz and the Blue Bird, for oboe and flute. Though they play beautifully together and have been friends since childhood, Mizore and Nozomi find that with graduation looming and the duet proving difficult, their friendship begins to buckle under the pressure. Interspersed with their story is the fantasy tale of Liz, drawn like a storybook, contrasting with the crisp realism of the school. 
 
(Source: Shout! Factory)

With another tournament fast approaching, Kumiko's band is doubling down on practice and discipline, leaving little time for sleep or other recreational activities. The redoubled practice schedule brings Kumiko and Reina closer together, but elsewhere in the band, it seems like drama threatens to tear the group's unity apart. The ghost of the prior year's mass band exodus still haunts many of Kumiko's classmates, and with former band member Nozomi Kasaki now asking to return, it seems like the grudges of the past will soon be impossible to ignore. 

(Source: Anime News Network, edited)

 
Note: The first episode aired with a runtime of ~48 minutes as opposed to the standard 24 minute long episode.

Chikai Maki