See In AO 1

Kyouya, a teacher at Andrude Ocean School, unknowingly captivates Miyu—the girl he once saved—who yearns for him in secret. Her twin, Yumi, an android bearing Miyu’s implanted memories, aids her pursuit but finds her own heart torn between devotion to Miyu and growing desire for Kyouya. Meanwhile, Kyouya crosses paths with Yui, the younger sister of his lost love Masumi, igniting bittersweet passions tangled in longing and the echoes of the past.