Yoru is an enigmatic entity inhabiting the Night World, a dream realm accessed during sleep. He acts as a guide for individuals facing unresolved emotional turmoil or loss, facilitating their journey toward acceptance without imposing direct solutions. His appearance is non-human, distinctly avian in form, contributing to the realm's ethereal atmosphere.

His background remains undisclosed. His development unfolds through interactions with three protagonists:
- For Chiyo, a young girl grieving her deceased dog, Yoru introduces the Night World's starless landscape. He accompanies her through its abstract, painterly environments—watercolor hillsides and luminous flora—as she processes sorrow. The realm gradually brightens with her emotional catharsis.
- He guides Tsumugi, a middle schooler struggling with jealousy after her best friend expands their social circle. Yoru observes her navigate a labyrinth symbolizing isolation, intervening only when she acknowledges her feelings. His presence helps her reconcile the conflict independently.
- With Akatsuki, an adult artist disillusioned by career failures, Yoru’s realm evokes forgotten memories. He supports her rediscovery of a childhood sketchbook and a friend's encouraging letter, reigniting her passion for painting.

Yoru's methodology emphasizes passive guidance: he provides a safe space for introspection but never forces resolutions or judges vulnerabilities. The Night World's shifting visuals—where crayon-textured stars emerge and trees swirl—reflect his influence in manifesting metaphors for emotional healing. Though his motivations remain unexplored, his consistency across encounters suggests a foundational purpose as a guardian of forgotten or abandoned memories.