Igarashi, Daisuke

Brothers Umi and Sora discover they are not the only ones deeply connected to the ocean, but when a mysterious man--a wunderkind--lures Sora away by promising him answers, Umi falls into a deep depression and Ruka helps her new friend find his brother.

Trapped within an undersea cave with Umi, Ruka begins hearing a strange voice that she eventually discovers is the key to determining the next stage in her journey.

Ruka is drawn to the aquarium where her dad works and the two strange boys, Umi and Sora, that she meets there, and soon all three are caught up in the mystery of the disappearance of fish from all over the world.

Brothers Umi and Sora discover they are not the only ones deeply connected to the ocean, but when a mysterious man--a wunderkind--lures Sora away by promising him answers, Umi falls into a deep depression and Ruka helps her new friend find his brother.

When Sora disappears into the night sea, Ruka is traumatized. But the meteorite that Sora made her swallow helps Ruka lead Umi and Anglade out to the open sea. It is there that Ruka begins to understand her past and how they all came to be connected.

As a child, Ruka saw a ghost in the water at the aquarium where her dad works and now feels drawn toward the aquarium. Ruka meets Umi and Sora, two mysterious boys who were raised by dugongs and hear the same calls from the sea the she does. Ruka's dad and the other adults who work at the aquarium are barely aware of what Ruka, Umi, and Sora are experiencing as the kids find themselves involved in the mysterious worldwide disappearance of the oceans' fish.