Tokyo is in a time of societal upheaval following the Ryunka accident. To make matters worse, the aliens who are directly responsible for the disaster have escaped the Space Federation and are hiding on Earth. Birdy Cephon Altera, a Space Federation officer, and Tsutomu Senkawa, a high schooler, are entrusted with apprehending the fugitives and bringing them to justice. However, the outlaws face an unanticipated problem when they become the target of a vengeful assassin. Birdy now has to deal with the craziness of everyday life while also figuring out who the assassin is before any more escapees are killed.