A young insect buff from Hokkaido captures a Papilio memnon butterfly, which is not supposed to be present in that area. The larva of a Papilio memnon sticks to someone in Nagasaki and sets out on a journey to the east. As the larva travels to Hagi, Hiroshima, Kyoto, Osaka, Hong Kong, Yokohama, and Tokyo, various loves and human dramas unfold.
