If you loved Love, Chunibyo & Other Delusions! Rikka Version, try Sound! Euphonium The Movie: May the Melody Reach You!
A bridge between a film you've already seen and one most people haven't. Sound! Euphonium The Movie: May the Melody Reach You! has roughly 4.2× fewer votes than Love, Chunibyo & Other Delusions! Rikka Version — it's a deeper cut, not a mainstream recommendation. Here's what they share, and what the second one does that the first one doesn't.

Love, Chunibyo & Other Delusions! Rikka Version

Sound! Euphonium The Movie: May the Melody Reach You!
What they share
Both films are directed by Tatsuya Ishihara, and they both carry the bittersweet, tender mood tags, and they sit in Animation / Drama territory. If that's the register that drew you to Love, Chunibyo & Other Delusions! Rikka Version, the second film will land in a comparable space — through a different lens.
What Sound! Euphonium The Movie: May the Melody Reach You! is
Hibike! Euphonium meets Glee minus the choreo. A first-chair euphonium fades out before nationals forcing her rival to scramble for a replacement on tuba. A 2017 slice-of-life where the music makes the friendships.