If you loved The Garden of Sinners: Remaining Sense of Pain, try Riki-Oh: The Wall of Hell
A bridge between a film you've already seen and one most people haven't. Riki-Oh: The Wall of Hell has roughly 4.7× fewer votes than The Garden of Sinners: Remaining Sense of Pain — 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.

The Garden of Sinners: Remaining Sense of Pain

Riki-Oh: The Wall of Hell
What they share
Theyboth carry the atmospheric, cozy, cult, foreign gem mood tags, and they sit in Action / Animation / Drama / Fantasy territory. If that's the register that drew you to The Garden of Sinners: Remaining Sense of Pain, the second film will land in a comparable space — through a different lens.
What Riki-Oh: The Wall of Hell is
You arrive at a corporate prison in a ruined 1990s Tokyo. You're Riki-Oh, and your super-powered fists landed you here. But the prison is run by something worse than the guards: four inmate overlords. The animation's extreme gore broke taboos, earning it a cult following.