Between 1990 and 1991, Viz experimented with a graphic novel line called the Viz Spectrum imprint. Graphic novel lines were an oddity at the time, but this one's also an anomaly among modern graphic novel lines as well. Viz was publishing more mature titles at the time. Their three launch titles from 1988 were all men's titles in sci-fi and historical genres, and there were also contemporary action series that came later. The Spectrum books are of a similarly mature flavor, though in genres that we don't often see translated today. These books are also all 70 pages, or two comic issues. The graphic novels themselves are oversized deluxe editions, still paperback, but with a lot more effort going into the presentation (vellum pages, vinyl covers, some foil embossing, et cetera). Each volume also contains an interesting essay in the back related to the content or artist. The books are pretty solid, and the line is obscure enough that it's worth visiting.
Hotel Harbour View - Written by Natsuo Sekikawa, Art by Jiro Taniguchi (1 volume)
Hotel Harbour View is probably the most approachable and well-known of these books. Art by Jiro Taniguchi helps keep it from obscurity. It's his early work, so it's not quite as detailed as his modern stuff, and there's not a whole lot of backgrounds. Character designs are a little rough as well, but the main character in the first story looks like Peter Falk, which is something. There is a spectacular slow-motion bullet sequence that looks great to this day, and that alone is worth the price of admission. The book has two stories in it, and the first, the titular Hotel Harbour View, is the one that ends with the bullet sequence. It was my favorite of the two, as it plays out like a bizarre practical joke with a lot of pulpy, noir-ish elements to it. There's not a whole lot of dialogue, and Taniguchi's art does a good job of carrying the narrative. The second story is in two parts, and follows one of the women in the first story. Once again, there are many dialogue-light sequences, and lots of gunplay and action. It has a fantastic ending as well, but this one is darker than the first. Both stories also take advantage of an international setting, with Hong Kong serving in the first and the second starting in France. This book was available new up until a few years ago, but looks a bit harder to track down at the moment. Used copies are hovering around $10, but the vinyl jackets are brittle, and I'm not sure whether they'd be included on a secondhand copy.
Shion: Blade of the Minstrel - Yu Kinutani (1 volume)
This was my favorite of the three volumes for the art alone, though the worst of the three story-wise. This has detailed, ink-heavy fantasy artwork inspired by European comics. The story itself is also a Western-style demon slaying affair, with a hero traveling around to kill monstrosities. Like Hotel Harbour View, Shion also contains two short stories. The first is more of an illustrated narrative, with explanations going along with the illustrations in each panel. Narration like that is almost nonexistent in manga, and to have a whole story of it is almost unheard-of. This was likely chosen for translation because it resembles a well-illustrated western story so much. The stories are very simple, however. The first story is about the main character, called Minstrel, getting revenge against the demon that possessed his father and ate Minstrel's eye. The second is about Minstrel trying to figure out how to slay twin sorcerers and getting advice from various sources. Unfortunately, it's a very episodic series that we never saw any more of in English, it doesn't really have a beginning or end, and it's nothing we haven't seen before. But it's fairly interesting as one of the most heavily western-inspired manga volumes I've seen, and I am a huge fan of the artwork. This is out of print, but readily available and cheap online.
Saber Tiger - Yukinobu Hoshino (1 volume)
Hotel Harbour View is contemporary crime/noir, and Shion is fantasy, so Saber Tiger is hard sci-fi, and the only other volume I know of in the Viz Spectrum imprint. Yukinobu Hoshino had another series released by Viz sometime later, another hard sci-fi collection of short stories called 2001 Nights. Like the other Viz Spectrum books, Saber Tiger is two short stories. The first, the titular Saber Tiger, is a story of time travel. The human race is doomed due to the gene pool failing in the far future. In order to increase the chances of survival, a group of time travelers go back to the ice age to save the lives of a large group of primitive humans, thus deepening the gene pool and staving off extinction. The time travel elements are surprisingly well-explained for such a short story, and there are some flaws, but it's a tight effort. The title comes from the fact that the people of the future must fight saber tigers in order to help the group of prehistoric humans survive. The second story is called The Planet of the Unicorn, which is about a search party finding a planet exactly like Earth. They release a group of animals to conduct a 5-year study to see if the planet is inhabitable. But the ship crashes on the planet's surface, and the crew is forced out into the environment. After removing their helmets, they find out the planet is plagued by "rotation noise," which is a terrible sound that drives all creatures from the outside mad. There's some struggles among the crew, some mythological ties, and other nice touches throughout. It's a great little story, but like the first, it would have benefited from being expanded. Of the three volumes, I would say this was the most unusual and worth seeking out if you're at all interested in hard sci-fi. Much like Shion, nobody knows this exists, and while it is out of print, it can be obtained cheaply online.