If you loved High School of the Dead: Drifters of the Dead, try Attack on Titan: Chronicle
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

High School of the Dead: Drifters of the Dead
→
Try this next

Attack on Titan: Chronicle
What they share
Both films are directed by Tetsuro Araki, and they both carry the foreign gem mood tag, and they sit in Adventure / Animation territory. If that's the register that drew you to High School of the Dead: Drifters of the Dead, the second film will land in a comparable space — through a different lens.
foreign gem
What Attack on Titan: Chronicle is
You wake in a city whose walls shelter from Titans but divide you from the world. Then the colossal breaks through. The director pares the first three seasons into a two-hour sprint, taut walls become battlegrounds. The film leaves you standing where the story began, humbled by its pace.