Garo - Vanishing Line
牙狼<GARO> -VANISHING LINE- (original)
In a prosperous city named Russell City, an omen that threatens to shake its world begins to move within it. A man named Sword is the first to hear the first stirrings of the plot, and throws himself into a shadow war in order to expose it. His only clue is the key word "El Dorado." He meets Sophie, a woman searching for her missing older brother who has only left her with the same words: "El Dorado." With Sword having also lost his younger sister in the past, both are drawn together by the words, and work together to find out its meaning.
Starring Rie Kugimiya, Tomokazu Seki
It's a animation and sci-fi & fantasy show, and has a rating of 6.8 out of 10 from Imdb which is usually fine for this kind of show.
Watch it here
Not found streaming from Netherlands.