A kid arrives expecting a normal summer visit. His aunt has other plans, she's going to walk him through the worst day in human history, not as a lesson, but as something she lived through. By the time he understands what she's asking him to carry, the show has already changed what he thought peace meant.
Kazuki boards a bullet train bound for Hiroshima, eager to spend his summer break with relatives he barely knows. What begins as a simple vacation becomes something far more profound when his aunt takes him through the city, sharing stories from August 1945 that still shape the lives of those who survived. Through her memories and firsthand accounts, the weight of that single day unfolds before him: the destruction, the loss, the impossible choices people made to endure. Kazuki discovers that his aunt carries more than just nostalgia; she carries the scars and lessons of a tragedy most people only read about in textbooks. As she speaks, the teenager begins to understand what peace truly means, not as an abstract ideal but as something fragile and hard-won. The journey becomes less about sightseeing and more about witnessing history through the eyes of someone who lived it, forcing Kazuki to reckon with how the past shapes the present and why remembrance matters.