[Machine Translation] Sixth grader Yuta was visiting a dam deep in the mountains, a place that holds fond memories of his late father. However, he is suddenly struck by a thunderstorm, slips, and faints. When he awakens, he sees a village that was supposed to have sunk into the dam. In the village in the 1970s, Yuta meets Kenzo, a boy his age, and a girl like a younger sister, Saeko. The boy's last and best summer vacation begins, along with the lost original landscape of Japan! This is the first volume of a nostalgic yet sad touching fantasy depicting the eternal summer vacation that is in everyone's heart.