Gamora: LOST WORLD

Heian-era Japan. Totsugawa Village.

While out hunting, the three brothers—Ichirota, Jirota, and Saburota—hear strange noises coming from the direction of Kuchihokora. When they head in that direction, a massive torrent of water gushes out from deep within the shrine, and a gigantic monster, Gamora, appears. After attacking the village, Gamora returns to the shrine, but…

The scene shifts to the present day. Sarutobi, a genius boy, was heading toward Gamora Village with his assistant, Shikishima…

(Source: Kaiki Manga no Anagura, translated)

Note: Originally planned as a ten-volume scifi epic, only three volumes were published in the end. In 1998, it was re-released with a brand-new chapter, which is included in this entry.