If you loved Zombie Self-Defense Force, try Eat the Schoolgirl: Osaka Telephone Club
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.

Zombie Self-Defense Force

Eat the Schoolgirl: Osaka Telephone Club
What they share
Both films are directed by Naoyuki Tomomatsu, and they sit in Horror territory. If that's the register that drew you to Zombie Self-Defense Force, the second film will land in a comparable space — through a different lens.
What Eat the Schoolgirl: Osaka Telephone Club is
Osaka, midnight, summer. A payphone flush with blood-red graffiti. A girl’s voice on the other end whispers about skin and sound. Two young cutouts split rent and yakuza snuff tapes. One rocks in front of a dial tone, twitching between his own filthy calls. The other records wet smacks over corpses, keeps a younger sister’s school photo taped to every wall. Naoyuki Tomomatsu pinches 90s J-horror cheapness until it gushes sticky.