Gate Keepers 21

Hunting interdimensional monsters called Invaders using a Gate — basically a superpower she was born with and never asked for — is the last thing Ayane Isuzu wants on top of her already miserable social life, where she goes to school and avoids conversation at all costs. It's 2001, Japan feels like it's rotting from the inside out, and the secret organization that used to fight these things has quietly fallen apart over the last three decades. Now it's just a handful of burnt-out Gate Keepers operating underground, and Ayane is one of the few still showing up — mostly out of resentment toward her absent father rather than any heroic impulse. Then a bubbly classmate named Miu stumbles into her world, discovers she has Gate abilities of her own, and suddenly Ayane has a partner she absolutely did not want. Oh, and the two most dangerous enemies from the original war are back. This is a six-episode OVA from Gonzo, and it leans hard into darkness — societal decay, personal grief, and characters who are genuinely struggling. If you liked the psychological weight of Neon Genesis Evangelion or the bleak atmosphere of Blue Gender, this scratches a similar itch. It's quieter and more internal than typical mecha fare, and the soundtrack gives the whole thing this haunting, melancholy texture that sticks with you. Don't go in expecting optimism.