Ep. 1: Mari enrolls in Kaihō Academy and encounters mysterious events involving Hagino and an alien ship.

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Mari Wakatake resents being sent by her grandmother to Kaihō Academy. During the journey, she observes a girl standing on a rock surrounded by birds. Upon arrival, the headmaster meets Mari and learns from her attorney that she lost her memories following an incident on Kamioki Island five years ago. A student named Michiko Kōzuki shows Mari around the campus. In her dorm, the leader Hiroko Funatsumaru introduces Mari to Hagino Senkouji, who suddenly chokes Mari while her eyes turn blue. Mari flees in anger but is comforted by Michiko, who advises her to befriend Hagino. At dinner, Mari attacks Hagino again. Later that night, Mari follows Hagino outside and witnesses a giant alien ship rising from the water.