Mermaid Forest - 1x10 - Promised Tomorrow (Part I)- Followmy.tv

In a flashback to 60 years before, a girl, Nae, tells her servant, Sokichi, and Yuta that local villagers used mermaid ash to create the Red Valley, a field of perennially blooming red flowers. Elsewhere Yuta heard that a villager killed a nun to steal the ash, but the nun came back to life and killed many of the villagers. When Yuta leaves, Nae disappears. The village holds a funeral for her, even though there's no body. Over the decades, Eijiro, Nae's former fiance, buys the village land. In the present, Mana finds one of Eijiro's men beating a girl named Nae. Nae kills the man, but two other men kill Mana. Eijiro, who keeps Nae confined on his estate, realizes Mana is immortal when she revives. Meanwhile, Sokichi, having met up with Yuta, tells Yuta that Nae is still alive unchanged and leads him to Eijiro's house, where Eijiro's men capture them. Nae kills some of Eijiro's men and escapes with Mana. Eijiro orders his men to recapture Nae unharmed and to decapitate Yuta.