The 35-year-old protagonist operates as a Calcutec, a professional who encodes data for the System using specialized right- and left-brain division techniques. He prefers a quiet life of reading, watching old movies, and listening to records. In an alternating storyline, he exists as an amnesiac newcomer to a mysterious walled Town, where he is assigned the difficult task of working as the local Dreamreader.

An eccentric, elderly biologist and former System researcher who operates out of a highly secretive laboratory accessible only through Tokyo's subterranean waterways. He speaks with a thick accent and possesses brilliant but unpredictable scientific abilities. He assigns the protagonist an unusual and dangerous data shuffling task.

A 17-year-old girl who assists her grandfather with his secretive work and guides visitors through the dangerous underground passages of Tokyo. Homeschooled by her grandfather, she is highly capable, multilingual, and forward in her interactions. She wears exclusively pink clothing and handles crises with surprising calm.

A counterpart figure existing in both narrative threads. In Tokyo, she is a knowledgeable library worker who assists the protagonist with his unusual research requests and shares large meals with him. In the walled Town, she serves as a quiet guide for the Dreamreader, providing him with the beast skulls he needs for his work.

The physical shadow of the narrator, forcibly separated from him at the End of the World. Imprisoned in a cold enclosure within the Shadow Grounds, he retains the memories and emotions of the narrator's past life. He resents the rules of the Town and actively seeks a way to survive his separation.

The imposing, practical guardian of the walled Town at the end of the world. He controls the movement of the beasts, maintains the Town's boundaries, and strictly enforces the rules regarding newcomers, including the painful severing of their shadows.

An elderly, retired military man who lives next door to the narrator in the Town. He serves as a source of information about the Town's weather, seasons, and customs. He frequently shares meals and plays unusual games of chess with his new neighbor.

A diminutive operative working for the criminal organization known as the Factory. He is talkative and uses psychological pressure during interrogations, acting as the primary strategist of the two-man team sent to extract information from the protagonist.

A massive former wrestler who acts as the physical muscle for the Factory's operations. He accompanies Junior during home invasions, using his enormous strength to destroy property and physically intimidate targets.

An exile from the Town who lives in the Woods and maintains the Power Station. He lives a solitary life, growing his own food and collecting discarded items from the Town, including musical instruments he enjoys looking at but cannot play.