Kuromukuro

Kuromukuro takes place in the early 21st century at the United Nations Kurobe Research Institute in Japan, where scientists from around the world study an ancient artifact discovered during the construction of the Kurobe Dam. Yukina Shirahane, a high school student and daughter of the facility's head scientist, stumbles upon part of the artifact's puzzle while visiting her mother. Her discovery brings Kennosuke Tokisada Ouma, a samurai from the Sengoku era, into her life. As Earth faces an extraterrestrial threat, Yukina and Kennosuke form an unlikely alliance to defend their planet.