There's a legend that claims consuming mermaid flesh grants immortality, but this tale carries a darker undertone - the eater may perish or transform into a monster. The young man Yuta has been traveling Japan in search of mermaids not to achieve eternal life, but to lift his curse of everlasting existence. Five centuries ago, he ate a mermaid; now, he seeks a cure, believing that mermaids hold the key to breaking his spell. During his journey, he discovers a concealed village inhabited by mermaids who dwell in an underground community centered on murdering and consuming young human females to preserve their youth and immortality. Their most recent victim, Mana, is given mermaid flesh to eat as part of the recipe for becoming a perfect candidate for consumption. Yuta assists her in escaping, and they embark on a journey to live ordinary lives.
Ningyo Series began publication in Shounen Sunday Zoukan and later moved to Weekly Shounen Sunday. It was published sporadically during its serialization. The original Japanese release was two wideband volumes and was incomplete; the second was complete in three small size volumes.The series was first published in English in the 1993 March issue of Animerica—Anime & Manga Monthly, a magazine published by VIZ Media. This magazine printed the first two story arcs of the first volume in Japanese. The remaining stories were subsequently published in comic book format by VIZ Select Comics, with 4 issues to each part, titled Mermaid Forest, Mermaids Dream, Mermaids Promise, Mermaids Scar, Mermaids Gaze and Mermaids Mask, published from 1993 to 1995. The series was additionally printed in standard tankoubon format by VIZ Graphic Novels, who printed the series in three volumes, titled Mermaid Forest, Mermaids Scar and Mermaids Gaze, from December 6, 1994 to March 8, 1997. VIZ Media re-published the title as a four-volume series, this time as Mermaid Saga from July 14, 2004 to December 22, 2004, in the original right-to-left order. The series was also published in Argentina by LARP Editores as Cuentos de Sirenas from November 2008 to April 2009.