If you loved Fireworks, try Kizumonogatari Part 2: Nekketsu
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.
What they share
Both films are directed by Akiyuki Shinbo, and they both carry the mindfuck mood tag, and they sit in Animation / Fantasy territory. If that's the register that drew you to Fireworks, the second film will land in a comparable space — through a different lens.
mindfuck
What Kizumonogatari Part 2: Nekketsu is
Snowflakes fall on a deserted street at dusk a lone streetlamp hums Koyomi faces vampire hunters in dark alleys A classic tale of supernatural struggle unfolds in modern anime style

