Sora no Naka

In 200X, an unexplained explosion happens during a supersonic business jet test flight near Shikoku. A month later, a similar incident occurs during a Japan Air Self-Defense Force flight between Gifu and Shikoku. In Kochi, close to where one of the planes crashed, a boy named Shun walks along the beach. His father was a crew member on the downed military aircraft. While there, Shun discovers an unusual, soft object washed up on the shore.