The visual perspective is always that of the cockroaches, and the background is live-action for the human characters. Cockroaches are numerous in the apartment of divorced Saito, whose loneliness & depression have left him close to suicidal. He is unable to clean up his apartment so lives and pines and drinks alone in the filth he has generated.
From the point of view of the cockroaches, Saito is a kind overlord who seeks only the happiness of cockroachkind. The younger generation of cockroaches has known only peace and plenty, with no one out to kill them, and junkfood cartons scattered everywhere like manna. Then Saito finds a girlfriend & begins to come out of his long depression. He begins to clean up his apartment and get his life back on the path to happiness. But from the cockroaches’ point of view, God’s wrath has descended, and Saito’s helpful girlfriend unleashes a veritable holocaust upon the stunned colony.
— Gokiburi-Tachi No Tasogare, 1987 (Twilight of the cockroaches)
