Ninomiya, Kikuko's male classmate, struggles with involuntary, bizarre facial expressions he makes primarily when thinking himself unobserved. This uncontrollable compulsion strains his social interactions and deepens his isolation.

He secretly built and maintains a miniature model world in a secluded spot, a meticulously crafted private world of imagination. He eventually shares this intimate creation solely with Kikuko, signifying profound trust and connection between them.

Their friendship forms through a bond over shared alienation and difficulty fitting in, fostering a natural, mysterious understanding devoid of romantic undertones. Their communication is easy and marked by mutual acceptance.

Within the narrative, Ninomiya acts as Kikuko's confidant, aiding her navigation of adolescence and her complex maternal relationship. His character grows by learning to trust and selectively reveal his hidden vulnerabilities.