This one makes you sit still and listen, which is a hell of a demand for a single OVA. The whole thing is built as testimony: a young man going door to door, pulling Heizou's legend out of Kumehachi, Hikojuu, and Omasa, people who know exactly what the man is capable of and admire him anyway. That structure is the flex, because you meet the Demonic Heizou through the mouths of the underworld before you ever get to judge him yourself, and the gap between the terror thieves feel and the warmth in those voices is the entire character. It's Edo as a working city of gutters, lanterns, and grudges, not a postcard. Watch it before the series and the man walks on screen already carrying his reputation like a coat. Best part is realizing the people telling his story are the ones he could have destroyed.
In the Edo Period, thieves and rogues fear Heizou Hasegawa, known as the Demon Heizou. A young man sets out to gather stories about him from Kumehachi, Hikojuu, Omasa and others who know and admire him. Through their accounts he learns about Heizou's early years, the informants who work for him, and how he came to be a police operative. He then travels to Heizou's private residence in Mejirodai, where Heizou's wife Hisae adds her own memories. Along the way, a question lingers over how the young man's own reason for seeking Heizou connects to the man himself.