It is very easy for adults to dismiss what a child sees. Whether it's mosquitoes that look like tiny fairies in the twilight or mermaids in the sea, things seen through the eyes of imagination can be written off with impunity by adults steeped in their cynicism or wishing to protect children from dangers either real or imagined. But to those who need to believe in mermaids and other fantastic creatures, these beliefs are central to their understanding of the world. That's where protagonist Tokiko of Mermaid Scales and the Town of Sand starts. Twelve-year-old Tokiko moves with her father back to her mother's hometown, a small coastal fishing village. The family had been living in Tokyo, but after the parents separated (something that was less official and more “mom just left”), Tokiko's dad decided to move in with his mother-in-law, a decision that is never really fully explained. Tokiko was last in the village when she was four when she almost drowned while her mother wasn't paying attention to her at the beach. In her memories, she is saved by a young merman, and she is determined to find him and thank him for saving her life. But was he really there? Or was he born of her frightened mind?

A lot is going on here, from the quiet pain of personal tragedies to the lengths adults will go to "protect" children from life, all tempered with the need to believe. The three main tragedies that are intertwined throughout the story are the town's history of tsunamis, Tokiko's experience with the merman, and the death by drowning of her new friend Yosuke's older brother. At least two of these have given rise to local belief and the sea god who needs to be appeased; the merfolk are said to be the messengers who convey humankind's devotion to him. The god in question is the Shinto water God Wadatsumi, one of the oldest deities in the Shinto pantheon mentioned in both the Kojiki and the Nihongi. The town has special rights dedicated to the god, and superstition keeps them largely from prying outside or child eyes. Like other drowning victims in other world mythologies, the merfolk are said to be those who were drowned in the tsunamis in the town's history, something that is primarily implied and shown to us long before we are actively told it. The link between the merfolk and death is thus established as a strong one right from the start, allowing readers to make educated guesses about what happened to Tokiko all those years ago and how it ties in with everything else around the town.

This power of implication is the strongest element of the story. We are consistently presented with Tokiko's need to believe versus what we start to suspect is the truth of everything. There is an adventure aspect to the story with all the quiet understatement of works like When Marnie Was There. For Tokiko and Yosuke, the adults in their lives are not giving them the answers they need, so they turn to the sea and its folklore to find their own answers. It's important to note that none of the adults are trying to hurt the children by not telling them things; they seem to truly believe that they are protecting them from the truth of the world. It's a familiar desire, one that many of us have experienced from both ends, and the only adult in town who is eventually willing to talk to them seems to do so because he recognizes that what's suitable for one child is not good for all children and that Yosuke and Tokiko need more truth than fiction to help them make sense of the world. Sometimes not knowing is worse than knowing, and it is equally valid that having a grain of truth can help polish up the pearl of your worldview.

Yoko Komori's art is simple in a deceptive way. Backgrounds are more detailed than characters but still give a sense of sparse dunes, battered houses, and the unfathomable depths of the sea. Despite the simplicity of the character designs, it is still obvious what everyone is thinking and feeling, and it is simple to tell them apart. The design for Tokiko's wayward mother is significantly cleaner in how she does her hair and how she dresses, which shows us that she doesn't fit in with the rest of the characters and isn't interested in doing so. At one point, her mother remarks that she had hoped that her daughter would exhibit more maturity once she had her own child, only to realize that having a child does not make someone become an adult. In some ways, this line sums up an essential piece of the book's philosophy: that adulthood means something different to everybody and that children grow at their own pace.

Although we are presented with mundane answers to the story's questions, the tail end of the book still leaves us – and Tokiko – with space to believe in mermaids and sea gods. What we know and how we make sense of that is up to us, and what we see out of the corners of our eyes may be the truth we need to hold on to.