This manga doesn't have much in the way of a plot. It centers around two people who are cursed to live forever, and that's really all there is to the main plot. The meat of the manga doesn't come from its main story, but rather its short story arcs, which all together make up a "saga," so to speak. Some of these arcs do have some interesting moments, but for the most part, they're forgettable, and some these arcs rely a lot on shock value.
I adore Rumiko Takahashi's art style. A large chunk of this manga came out early in Takahashi's career, and this was a time in which her style hadn't quite found its groove just yet. By the end of the manga, however, the art improves drastically. In fact, this is usually the case with most of Takahashi's older works, such as Maison Ikkoku and Urusei Yatsura. The improvement in the art isn't gradual like it is in the other series I just mentioned, however. This manga was on hiatus for a number of years, and when Takahashi finally finished it, the change in art was very sudden. It's difficult to judge the art because for most the manga, the artwork is only okay, and it's really only great for the last few chapters of the manga. The artwork is never unpleasant to look at, however, and it always carries the Takahashi charm.
This series only has two main characters, and neither of whom is very interesting. Both characters also seem to be lacking in the personality department. They aren't characters you're going to hate, but you also won't like them. You do see their relationship grow a bit, but you still don't get an emotional attachment. There are some semi-interesting characters among the story arcs, but they aren't really memorable either.
Overall, I enjoyed my time with Mermaid Saga. Kind of. It has some mildly entertaining moments, but it's never exciting, and there are some admittedly boring moments. It's not a bad manga, but it's not really a good manga. I personally wouldn't recommend this manga to anyone except for Rumiko Takahashi fans. Even then, I'd actually suggest watching the Mermaid Forest TV series over reading the manga. It tells the same story, but it's more entertaining in anime form. Really.
