Mark's older sister and a protagonist in the story, Karin has spent much of her life protecting Mark from their parents' erratic behavior. She works at a crane refuge and faces challenges of identity and validation throughout the story.

A neuropsychologist described as resembling a combination of Charles Darwin and Santa Claus, Weber is a protagonist who writes books on unusual neurological conditions. He grapples with self-doubt about his career and the ethical implications of his work with patients like Mark.

An attractive woman in her forties, Barbara is notable for her calm demeanor and serves as an important support for Mark. Her interactions with the main characters reveal complexities in her identity, though she keeps significant parts of her past hidden.

A thin and quiet character who values the natural world and pursues a vegan lifestyle. He struggles with his identity and has a complicated relationship with Karin, whom he supports while dealing with his own personal conflicts.

A practical and earthy character who is initially seen as a balance between human interests and nature but later reveals plans that could harm the environment. He shows a more passionate and grounded attachment to Karin compared to Daniel.