This one grabs you by the collar in the first five minutes and never bothers to explain itself, which is exactly the deal you signed up for. It is 1989 in its bones: the MacGuffin is a stolen AIDS anti-serum, the villain is an arms merchant, and the hero is a burned-out mercenary named John Kyosuke who gets pulled off the retirement bench because nobody else will do the job. Then the plot pulls the knife it was hiding all along, the people on the other end of his gun turn out to be family, and a straight revenge run becomes something he cannot shoot his way clean of. It runs a single OVA episode and ends like a pilot for a series that never showed up, which is half of why cult heads keep passing it around. Watch it for the era, the gun-metal grit, and the sheer nerve of a movie-length action manga adaptation that thinks 50 minutes is plenty.

John Kyosuke has retired, but he is forced back into action when an arms merchant kidnaps an American scientist who is carrying a cure for the AIDS virus. Kyosuke takes on the job of recovering the anti-serum. Along the way he learns that some of the people he is chasing are closely related, and that discovery changes what the mission means to him. The story is a single-episode action and adventure OVA from 1989.