Daemons of the Shadow Realm

One twin raised in daylight, the other locked in a cage — separated at the boundary of day and night, divided by fate, form the setup for Yomi no Tsugai, and it only gets stranger from there. Yuru lives a quiet life hunting in a remote mountain village while his sister Asa is confined and forbidden from seeing almost anyone, carrying out some duty nobody will explain. Then helicopters show up, armed men start killing villagers, and Yuru's sheltered world collapses in a single afternoon. Turns out the village was hiding a lot more than mountain folklore, and Yuru gets dragged into a world of Tsugai — paired supernatural entities bound to human wielders — as he tries to figure out what his family really is and why people want him dead. The supernatural pairing system is genuinely cool and feels distinct, not just "guy has a demon inside him" but something with its own rules and logic. The sibling dynamic between Yuru and Asa carries real weight too, since they've basically been strangers their whole lives despite being twins. If you liked the brother-sister bond and alchemy system in Fullmetal Alchemist, or the way Demon Slayer grounds its supernatural action in family ties, this hits similar notes with its own identity. Studio Bones Film is handling production with director Masahiro Andō (Sword of the Stranger), so expect the action sequences to deliver. It's a shounen manga adaptation that leans more into mystery and world-building than pure spectacle, which is a nice change of pace.