Oogi Shunpei is a high school student but also a professional treasure hunter. Under orders from his father, a former treasure hunter who has settled into a life of leisurely retirement, Shunpei travels the globe in search of treasures scattered across the world. One day, while journeying to Kalimantan to acquire a mysterious ruby ​​orb, he finds himself in conflict with a certain group of treasure hunters vieing for the same gem. This group, who call themselves the Dark Star Gang, is dedicated to collecting Sacred Orbs scattered throughout the world. Having successfully secured the ruby, Shunpei returns to Japan; however, shortly thereafter, Paucha—the guardian who had been protecting the ruby—tracks him down and arrives at the Oogi family home…