At the age of 12, Yuuta had suffered the loss of his father due to a tragic traffic accident one year prior. Seeking solace, he ventured to a secluded dam nestled within the mountains, a place where he and his father had enjoyed many happy memories together during previous summer vacations. However, during his visit, an unexpected thunderstorm erupted, causing Yuuta to slip and fall unconscious. Upon awakening, he found himself in a strange village, with no knowledge of how he had come to be there. He soon realized with shock and confusion that he had traveled back in time roughly 30 years, to a village that had long ago sunk beneath the waters of the dam. Despite the otherworldly circumstances, this unexpected journey became a cherished memory for Yuuta - a poignant reminder of a summer he spent in a time and place not meant for him.