Mikio Ōsawa, a withdrawn and shy fifth-grade student in Osaka's suburbs, struggles to express his feelings. He harbors romantic feelings for classmate Haruko Tezuka, hindered by his timidity. News of Haruko's impending move, delivered by his friend Megane, intensifies his emotional conflict and creates urgency to overcome his communication barriers. Supernatural intervention arrives when the ghost Cupio appears, offering to help Mikio confess.

Mikio's past includes a locally famous but traumatic history as the "occult miracle boy," possessing the ability to see ghosts. This experience caused psychological distress, leading to social withdrawal and repression of his supernatural perception. Haruko Tezuka also shares this ghost-seeing ability, though her reasons for urging Mikio to acknowledge his gift remain unexplained.

His character development culminates in a public confession to Haruko, requiring significant courage given his anxious nature. This moment amplifies when ghosts broadcast the confession globally across all screens, forcing Mikio to confront his fears on an unprecedented scale. The act represents a transition from paralyzing shyness to decisive emotional expression, facilitated by extraordinary circumstances.

Mikio's interpersonal relationships are primarily defined by interactions with Haruko, Megane, and the ghost Cupio. The resolution occurs when he successfully communicates his feelings to Haruko, achieving his primary objective despite external complications and concluding his depicted emotional arc centered on overcoming internal barriers through extraordinary intervention.