Book 1

When Ruka was younger, she saw a ghost in the water at the aquarium where her dad works. Now she feels drawn toward the aquarium and the two mysterious boys she meets there, Umi and Sora. They were raised by dugongs and hear the same strange calls from the sea as she does.Ruka's dad and the other adults who work at the aquarium are only distantly aware of what the children are experiencing as they get caught up in the mystery of the worldwide disappearance of the oceans' fish

Book 2

Umi and Sora are not alone in their strange connection to the sea. Forty years ago, Jim met another young boy with the same powers. As penance for letting the boy die, Jim has been searching the world for other children with those same ties to the ocean. Anglade, a wunderkind who was once Jim's research partner, lures Sora away with the promise of answers. This leaves Umi severely depressed, and it is up to Ruka to help her new friend find his brother. But time is quickly running out... When Ruka was younger, she saw a ghost in the water at the aquarium where her dad works. Now she feels drawn toward the aquarium and the two mysterious boys she meets there, Umi and Sora. They were raised by dugongs and hear the same strange calls from the sea that she does. Ruka’s dad and the other adults who work at the aquarium are only distantly aware of what the children are experiencing as they get caught up in the mystery of the worldwide disappearance of the ocean’s fish.

Book 3

The sea has a story to tell, one you’ve never heard before...

Reads R to L (Japanese Style). The sea has a story to tell, one you’ve never heard before...

Ruka is traumatized when Sora disappears into the night sea right in front of her. But although she refuses to speak of the incident, the meteorite Sora made her swallow is not so silent. It whispers to her from inside her body, and with its guidance she leads Umi and Anglade into the open ocean in search of answers. Surrounded by the sea, Ruka starts to see glimpses of the past that help her understand how Umi, Sora, Jim and Anglade all came to be connected.

Book 4

Jim, Dehdeh, and Ruka's mom finally track down Anglade's yacht, but neither the rogue scientist nor Umi and Ruka are on board. All that remains is a cryptic invitation to Jim. While Jim tries to figure out the game his ex-colleague is playing and Kanako dives into memories of her daughter Ruka, the strange sea-changes continue around the world.

Book 5

Long-awaited conclusion to the critically acclaimed series!

When Ruka was younger, she saw a ghost in the water at the aquarium where her dad works. Now she feels drawn toward the aquarium and the two mysterious boys she meets there, Umi and Sora. They were raised by dugongs and hear the same strange calls from the sea as she does.

After following Umi deep into the ocean, Ruka finds herself in an undersea cave where she hears a voice calling to her. She soon realizes it is the meteorite in her stomach, telling her the next step in her journey. The FINAL VOLUME of this majestic tale.