Chakuro of the Sea of Sand is the first chapter of Abi Umeda's manga Children of the Whales.
The story begins with the inhabitants of the Mud Whale solemnly holding a funeral for Benihi, one of their own. The Marked of the island lift her coffin with thymia, and place it into the sea of sand that surrounds their world. Chakuro, the archivist of the island, records the date (Day 2, Month 7, Year 93) and writes of Benehi. However, he is unable to hold back his tears and cries. Chakuro then narrates of his desire to write.
Chakuro then runs into Sami, his friend, who is teaching several of the younger Marked how to control their thymia. She teases him about his own lack of control over his thymia, and wonders if that's why he was appointed archivist. Chakuro recalls Benihi, their former teacher, and Sami asks him not to dwell on her and her death, or else they will never be at peace.
While Chakuro goes off to deliver his writings, he runs into Tobi, who asks him to cut a few leaves of the Oomasagochiku bamboo. Chakuro ends up accidentally cutting off the tops of some stalks, which crash to the ground. He flees, and goes to hide in Nezu and Ro's workshop, where they gift him a pair of goggles in exchange for his promise to bring back some good salvage.
Chakuro then runs into Mayor Taisha and her attendants, and talks about his motivations to write. He then goes to Suou, Sami's brother and the next in line to be the mayor, and turns his writing in. After he leaves, Chakuro then spots an island out on the sea of sand.
A reconnaissance team is set out to scout the island before they salvage it. Chakuro and Sami are both chosen to go. When they reach the island, they discover that it bear a striking resemblance to the Mud Whale. Chakuro ends up wandering away from the group, and stumbles upon a strange, cat-like creature. That creature leads him over to a alcove where a mysterious girl, clutching a bloodstained sword, rests. The girl, smiling and shedding tears, stumbles over to Chakuro and pushes him down, holding a sword to his throat.