0-Jigen no Oka

Overview

Toshio Yamagata, a young elementary school student, sheds tears every time he listens to the record "The Swan of Tuonela". When he listens to this record, a vivid image of a landscape with a large tree and a white wall appears in his mind, and he believes that this place is his hometown. Toshio's older brother investigates this mysterious phenomenon and discovers that the landscape is from the village of Lien Tao in Vietnam. Furthermore, it becomes clear that there are four other children from different countries who have had similar experiences. To unravel this mystery, these five children are gathered in Vietnam, leading to the revelation of a shocking truth.

Source: AniList