Nurse Yuuki provides medical care for Karin Shiraishi, a pneumothorax patient hospitalized in northern Hokkaido. She performs routine nursing tasks, monitors Karin's condition, and enforces restrictions like limited laptop use. Aware that Karin refuses surgery due to trauma from her father's death during a similar procedure, Yuuki begins anonymous email correspondence, posing as a "fan" of Karin's online dream journal.

Yuuki carefully selects photographs of Hokkaido travels sent through these emails, aiming to offer emotional support and combat Karin's isolation. These photos come from her boyfriend Dr. Amakasu's collection, inadvertently leading Karin to believe Dr. Amakasu is the sender. Yuuki sustains this supportive deception until Karin discovers identical photos on Dr. Amakasu's desk, prompting Yuuki's confession.

Her intervention strives to help Karin build trust and overcome her isolation. This effort contributes to Karin's eventual choice to undergo surgery after recognizing her self-centered behavior, particularly following her brother Mitsuru's collapse from exhaustion. Yuuki's relationship with Dr. Amakasu is confirmed, though the narrative provides no further personal backstory or development beyond this role.