If you loved Assassination Classroom the Movie: 365 Days' Time, try Aura: Koga Maryuin's Last War
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.
You already loved

Assassination Classroom the Movie: 365 Days' Time
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Aura: Koga Maryuin's Last War
What they share
Both films are directed by Seiji Kishi, and they both carry the cozy, foreign gem mood tags, and they sit in Animation / Comedy / Drama territory. If that's the register that drew you to Assassination Classroom the Movie: 365 Days' Time, the second film will land in a comparable space — through a different lens.
cozyforeign gem
What Aura: Koga Maryuin's Last War is
Apparently fantasy worlds are contagious. Satou Ichirou tries to behave normally at his new school. His attempt at normalcy is short lived.