The character known as "Lettore di Haiku" acts as a narrative voice reciting classical Japanese haiku poetry throughout the film. This voice provides thematic transitions between vignettes, using short poetic verses to juxtapose the Yamada family's everyday experiences with broader philosophical or seasonal reflections. The recited haiku frequently feature natural imagery or seasonal changes—such as autumn dusk, cicadas, or mountain paths—creating lyrical connections to the family's moments of humor, melancholy, or introspection.

Specific examples include the verse "No sign of death’s approach in the cicadas’ voices" during a hospital visit scene, "The scent of plums on a mountain path. Suddenly dawn" following a teenager's joyful phone call, and "Turn toward me. I’m lonely too. The autumn dusk" accompanying a scene of marital mundanity. These verses distill emotional or situational essences from the vignettes, elevating ordinary events into poetic meditations.

The haiku selections incorporate traditional seasonal references (kigo) and structural elements characteristic of classical Japanese poets like Matsuo Bashō. Their delivery functions as a cultural framing device, linking contemporary family life to established literary traditions without direct participation in the narrative.

No background, personal characteristics, or development across other media exist for this narrative role. The character does not appear in the sequel series "Nono-chan" or any official spin-offs, remaining exclusively a vocal presence in the original film.