Shinkai Shoujo

One year ago, Hikari Tanaka vanished into the ocean without a trace. Her miraculous return was made possible by the Deep-Sea King, who rescued her from the ocean floor and transformed her into something entirely new. Now known as a deep-sea girl, Hikari possesses extraordinary abilities drawn from the creatures of the abyss, fundamentally altering her existence and blurring the line between human and marine life. Her childhood friend, Yamada, is overjoyed to have her back after enduring a year of uncertainty and grief. However, his relief quickly gives way to confusion as he witnesses Hikari’s bizarre new traits—her body inexplicably emits light and turns completely transparent at times. These strange behaviors serve as constant reminders that the girl standing before him is no longer entirely the person he once knew. Despite the unsettling changes, Yamada’s deep romantic feelings for Hikari compel him to embrace her new reality. He resolves to accept every unusual aspect of her transformation, determined to stand by her side regardless of what she has become. Yet, navigating a relationship with someone who now belongs to the depths of the sea may prove far more complicated than his devotion alone can overcome.