This Monster Wants to Eat Me - S01

Hinako Yaotose has never fully recovered from the accident that claimed her family, leaving her haunted by the thought of disappearing into the ocean forever. Her only lifeline is her friend Miko Yashiro, though even that bond isn't enough to keep the darkness at bay when she's alone. Then, one summer, she encounters a strange girl with eyes as vast and serene as the sea-someone who stirs something in Hinako for the first time in years. While searching for the girl, Hinako is dragged underwater by a monstrous sea creature. Just as hope seems lost, the girl-Shiori Oumi-appears, revealing her own terrifying form as she kills the beast. But Shiori isn't here to save Hinako; like any predator, she only wants to devour her. The next day, Shiori shows up as a new transfer student in Hinako's class. To Hinako, this isn't a threat-it's a gift. At last, someone who might grant her silent wish for death has come.