Yūko, a junior high school student visiting Hiroshima Peace Memorial Park on a school trip, encounters a monument to Dr. Marcel Junod with her classmate Mii. Their curiosity about the monument and the doctor triggers an unexpected event, transporting them back in time to Europe in 1935. Arriving in the past, Yūko and Mii follow the path of the young Dr. Junod, then an International Committee of the Red Cross delegate. They witness his humanitarian efforts across conflict zones, starting in Ethiopia where he confronted attacks on medical workers and poison gas use. Their journey continues through Spain and other World War II European battlefields, observing Dr. Junod working to improve prisoner of war conditions, establish communication between prisoners and families, and secure routes for essential relief supplies.

Yūko witnesses the horrors of war and the moral challenges faced by humanitarian workers. She observes Dr. Junod's unwavering commitment to aiding those affected by conflict, regardless of affiliation. This exposure leads her to reflect on human suffering, resilience, and the ethical responsibilities of individuals in crisis. Through Dr. Junod's actions, like prioritizing aid over political divisions, Yūko gains insight into the principles of neutrality and compassion in humanitarian work.

These experiences prompt personal reflection on her own life and societal challenges. An ordinary student, her perspective shifts through direct exposure to historical events, emphasizing the impact of witnessing selfless dedication. The journey concludes with Yūko and Mii returning to their own time, carrying a deeper understanding of Dr. Junod's legacy and the lasting relevance of humanitarian values.