Blue Exorcist (2011)

S4E3 Hometown

Shura mysteriously disappears, prompting Mephisto to analyze her last known whereabouts. He concludes that she has likely returned to her hometown in Aomori Prefecture. Consequently, he sends Rin and Yukio on a mission to find her. As they dig deeper, the twins end up at Lake Towada, where they discover Shura in a fierce confrontation with Hachirotaro Okami, a formidable Hydra who has claimed dominance over the lake and its surroundings. Hachiro and his serpentine allies pressure Shura to honor a promise she made to him.