Riho Shihomi, a professional photographer, emerges as a significant mentor figure to Fu Sawatari. Fu deeply admires Riho's work and sends her own photographs, an act that reignites Riho's passion for her craft and prompts her to invite Fu to an exhibition. In return, Riho sends Fu a symbolic train ticket bearing no destination, embodying the open-ended possibilities of life's journey.

Their paths cross in person at Riho's exhibition, where a meaningful conversation unfolds about photography's power to connect people and capture transient moments of joy. Later, during a visit to Café Tamayura, Riho shares how photography became essential to her own life, further cementing her role as Fu's guide.

As Fu advances in her photographic pursuits, Riho consistently offers encouragement. In subsequent developments, Riho decides to leave Takehara for Tokyo, accepting a position at a small photography gallery – a career shift discussed with Fu during the Kaguya-hime Parade festival. During their farewell, Riho acknowledges Fu's substantial growth, reassuring her that constant mentorship is no longer needed as Fu has matured enough to forge her own path. Riho also reveals her own past reliance on a mentor, drawing a direct parallel to their relationship.

Riho's background includes inspiring Fu during a period of personal grief. Her decision to pursue opportunities in Tokyo marks the culmination of her character arc, with interactions consistently highlighting themes of artistic inspiration and the transmission of wisdom between photographers across generations.