Kazuyuki Sakamoto

Sakamoto is cheerful, relaxed and approachable. His smoking and casual demeanor can initially make him look unreliable, particularly beside the responsibilities associated with running a small school, but his behavior toward the children shows a more competent educator beneath that impression.

He is comfortable with the informal relationships typical of the island community. Rather than placing himself at a rigid distance from students and villagers, he participates naturally in local life and understands the personalities of the children under his care.

His temperament also fits the broader contrast Handa encounters on the island: people who may appear eccentric or overly casual by urban standards are often perfectly capable when circumstances require it.

Sakamoto is an experienced educator responsible for helping manage a very small rural branch school. Such an environment requires flexibility, since the limited number of pupils and close community ties make teaching substantially more personal than in a large urban school.

He understands the local children and is able to supervise them without suppressing the independence that characterizes their upbringing. His apparent casualness therefore coexists with practical competence.

Sakamoto appears as part of the adult infrastructure of the village, broadening Handa's experience beyond the children who constantly visit his house. Through the branch school and its staff, the story shows how Naru and the other younger residents are educated within their small community.

His presence also reinforces the interconnectedness of village life. Handa cannot neatly divide his neighbors into strangers, clients, teachers and children because the same people repeatedly encounter one another across school, work and community activities.

Rather than driving a major independent storyline, Sakamoto contributes to the setting that reshapes Handa's assumptions about adulthood and competence. The vice-principal's relaxed exterior is another reminder that seriousness does not always need to look like the rigid professionalism Handa initially values.

Naru Kotoishi is one of the young children within the branch school's community. Sakamoto is accustomed to the energetic independence that makes her such an overwhelming presence in Handa's life.

Sei Handa encounters Sakamoto through his increasing involvement with the village and its children. Sakamoto represents one of the established adults in the community into which Handa gradually settles.