Kaijuu Iro no Shima

Living on a small island without a single friend, middle schooler Chigawa Kon often laments that she has yet to experience "falling in love," unlike her peers. She frequently spends time near "the Hole," a cave by the sea where local legends claim a man-eating monster resides. One day, while she is with another girl who accidentally drops her smartphone into the ocean, they both fall from a cliff but manage to survive against the odds. It becomes apparent that Furuka is also feeling isolated.