Shota Sometani plays a physician with an unsettling approach to elder care in “The A-Care: Disusebody.” | © 2025 N.R.E. As Japan’s population grays, domestic films about the problems of the elderly — and dystopian responses to them — have proliferated. Chie Hayakawa’s “ Plan 75 ” (2022) imagines a near-future in which the government encourages senior enrollment in an assisted suicide program. And in Banmei Takahashi’s “ Euthanasia Special Zone ” (2026), Japan has legalized active euthanasia. Koki Yoshida’s “The A-Care: Disusebody” posits yet another sinister solution for dealing with inconvenient elders: Cut off their limbs. But the film is not straight-up body horror.…