Folktales from Japan S01 E117 The Treasure Swamp / Tatsukohime / Kurohime and the Dragon

A rich man learns of a treasure in a swamp and forces his servants to drain it. Tatsuko goes to a shrine in the mountain every night seeking eternal beauty. The black dragon, who is the master of a huge swamp, wants to marry the beautiful Kurohime. Source: crunchyroll