One day, two young students in Hiroshima, Mocchi and Ayaka, meet an odd American tourist named John and give him a tour of their city. At the same time, a mysterious light appears in the night sky above Hiroshima, and a prominent researcher arrives to pursue the mystery. Meanwhile, a schoolboy called Yuya dreams of a girl who takes him to see the Hiroshima of old. Mysterious stories from Hiroshima's past and present intersect and eventually become one. An old, long forgotten song for peace is heard once again.